80 results on '"Ming-Yih Liu"'
Search Results
2. Sulfation of benzyl alcohol by the human cytosolic sulfotransferases (SULTs): a systematic analysis
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Katsuhisa Kurogi, Lingtian Zhang, Masahito Suiko, Ming-Cheh Liu, Alaina M. Schnapp, Yoichi Sakakibara, Frederick E. Williams, and Ming-Yih Liu
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0301 basic medicine ,Kidney ,Human liver ,Chemistry ,organic chemicals ,Toxicology ,Small intestine ,03 medical and health sciences ,Cytosol ,chemistry.chemical_compound ,030104 developmental biology ,Sulfation ,medicine.anatomical_structure ,Biochemistry ,Caco-2 ,Benzyl alcohol ,In vivo ,medicine - Abstract
The aim of the present study was to identify human cytosolic sulfotransferases (SULTs) that are capable of sulfating benzyl alcohol and to examine whether benzyl alcohol sulfation may occur in cultured human cells as well as in human organ homogenates. A systematic analysis revealed that of the 13 known human SULTs, SULT1A1 SULT1A2, SULTA3, and SULT1B1 are capable of mediating the sulfation of benzyl alcohol. The kinetic parameters of SULT1A1 that showed the strongest benzyl alcohol-sulfating activity were determined. HepG2 human hepatoma cells were used to demonstrate the generation and release of sulfated benzyl alcohol under the metabolic settings. Moreover, the cytosol or S9 fractions of human liver, lung, kidney and small intestine were examined to verify the presence of benzyl alcohol sulfating activity in vivo. Copyright © 2015 John Wiley & Sons, Ltd.
- Published
- 2015
3. Sulfation of opioid drugs by human cytosolic sulfotransferases: Metabolic labeling study and enzymatic analysis
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Ming-Yih Liu, Yoichi Sakakibara, Masahito Suiko, Andriy Chepak, Katsuhisa Kurogi, Ming-Cheh Liu, and Michael T. Hanrahan
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Narcotic Antagonists ,Pharmaceutical Science ,Nalorphine ,Pharmacology ,Kidney ,Sulfur Radioisotopes ,Article ,Naltrexone ,Cytosol ,Sulfation ,Intestine, Small ,medicine ,Humans ,Levorphanol ,Lung ,Sulfates ,Chemistry ,Hep G2 Cells ,Nalbuphine ,Analgesics, Opioid ,Liver ,Opioid ,Oxymorphone ,Morphine ,Sulfotransferases ,medicine.drug - Abstract
The current study was designed to examine the sulfation of eight opioid drugs, morphine, hydromorphone, oxymorphone, butorphanol, nalbuphine, levorphanol, nalorphine, and naltrexone, in HepG2 human hepatoma cells and human organ samples (lung, liver, kidney, and small intestine) and to identify the human SULT(s) responsible for their sulfation. Analysis of the spent media of HepG2 cells, metabolically labeled with [35S]sulfate in the presence of each of the eight opioid drugs, showed the generation and release of corresponding [35S]sulfated derivatives. Five of the eight opioid drugs, hydromorphone, oxymorphone, butorphanol, nalorphine, and naltrexone, appeared to be more strongly sulfated in HepG2 cells than were the other three, morphine, nalbuphine, and levorphanol. Differential sulfating activities toward the opioid drugs were detected in cytosol or S9 fractions of human lung, liver, small intestine, and kidney, with the highest activities being found for the liver sample. A systematic analysis using eleven known human SULTs and kinetic experiment revealed SULT1A1 as the major responsible SULTs for the sulfation of oxymorphone, nalbuphine, nalorphine, and naltrexone, SULT1A3 for the sulfation of morphine and hydromorphone, and SULT2A1 for the sulfation of butorphanol and levorphanol. Collectively, the results obtained imply that sulfation may play a significant role in the metabolism of the tested opioid drugs in vivo.
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- 2014
4. Sulfation of Buprenorphine, Pentazocine, and Naloxone by Human Cytosolic Sulfotransferases
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Masahito Suiko, Teng Yan, Yoichi Sakakibara, Yoonjung Lee, Katsuhisa Kurogi, Mei Chen, Ming-Cheh Liu, Bo Shi, and Ming-Yih Liu
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Drug ,Pentazocine ,Carcinoma, Hepatocellular ,media_common.quotation_subject ,Narcotic Antagonists ,Clinical Biochemistry ,Pharmaceutical Science ,(+)-Naloxone ,Pharmacology ,Sulfation ,Cytosol ,In vivo ,medicine ,Humans ,Pharmacology (medical) ,media_common ,Chemistry ,Naloxone ,Sulfates ,Liver Neoplasms ,Biochemistry (medical) ,Metabolism ,Hep G2 Cells ,Buprenorphine ,Analgesics, Opioid ,Opioid ,Sulfotransferases ,medicine.drug - Abstract
Buprenorphine, pentazocine, and naloxone are opioid drugs used for the treatment of pain and opioid dependence or overdose. Sulfation as catalyzed by the cytosolic sulfotransferases (SULTs) is involved in the metabolism of a variety of xenobiotics including drug compounds. Sulfation of opioid drugs has not been well investigated. The current study was designed to examine the sulfation of three opioid drugs, buprenorphine, pentazocine, and naloxone, in HepG2 human hepatoma cells and to identify the human SULT(s) responsible for their sulfation. Analysis of the spent media of HepG2 cells, metabolically labeled with [(35)S]sulfate in the presence of each of the three opioid drugs, showed the generation and release of their [(35)S]sulfated derivatives. A systematic analysis using eleven known human SULTs revealed SULT1A3 and SULT2A1 as the major responsible SULTs for the sulfation of, respectively, pentazocine and buprenorphine; whereas three other SULTs, SULT1A1, SULT1A2, and SULT1C4, were capable of sulfating naloxone. Enzymatic assays using combinations of these opioid drugs as substrates showed significant inhibitory effects in the sulfation of buprenorphine and pentazocine by naloxone. Differential sulfating activities toward the three opioid drugs were detected in cytosol or S9 fractions of human lung, liver, kidney, and small intestine. Collectively, these results imply that sulfation may play a role in the metabolism of buprenorphine, pentazocine, and naloxone in vivo.
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- 2012
5. Human Cytosolic Sulfotransferase SULT1A3 Mediates the Sulfation of Dextrorphan
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Ming-Yih Liu, Masahito Suiko, Yoichi Sakakibara, Akihiro Yamamoto, Ming-Cheh Liu, Katsuhisa Kurogi, and Isaac T. Schiefer
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0301 basic medicine ,Pharmacology ,Sulfotransferase ,Dextrorphan ,Chemistry ,Pharmaceutical Science ,General Medicine ,Dextromethorphan ,Hep G2 Cells ,Arylsulfotransferase ,03 medical and health sciences ,Cytosol ,030104 developmental biology ,Sulfation ,Biochemistry ,Caco-2 ,Cell culture ,medicine ,Humans ,Caco-2 Cells ,Excitatory Amino Acid Antagonists ,Active metabolite ,medicine.drug - Abstract
Dextrorphan, an active metabolite of the antitussive dextromethorphan, has been shown to be subjected to sulfation by several zebrafish cytosolic sulfotransferases (SULTs). We were interested in finding out which of the human SULT(s) is(are) capable of catalyzing the sulfation of dextrorphan, and to verify whether sulfation of dextrorphan may occur in cultured human cells and human organ cytosols. Data from the enzymatic assays showed that, of all thirteen known human SULTs, SULT1A3 displayed the strongest dextrorphan-sulfating activity. Cell culture experiments using HepG2 human hepatoma cells and Caco-2 human colon carcinoma cells incubated with [(35)S]sulfate together with varying concentrations of dextrorphan revealed indeed the production and release of [(35)S]sulfated dextrorphan in a concentration-dependent manner. Additionally, significant dextrorphan-sulfating activity was detected in human liver, small intestine and lung cytosols. Taken together, these results provided a biochemical basis for the sulfation of dextrorphan in humans.
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- 2016
6. Sulfation of ractopamine and salbutamol by the human cytosolic sulfotransferases
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Kyoung-A. Ko, Masahito Suiko, Ming-Cheh Liu, Yoichi Sakakibara, Katsuhisa Kurogi, Ming-Yih Liu, and Garrett Davidson
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Sulfotransferase ,Dopamine ,Biochemistry ,Substrate Specificity ,chemistry.chemical_compound ,Cytosol ,Sulfation ,In vivo ,Phenethylamines ,Sulfur Isotopes ,medicine ,Humans ,Albuterol ,Molecular Biology ,Sulfates ,Chemistry ,Regular Papers ,Hep G2 Cells ,General Medicine ,Metabolism ,Hydrogen-Ion Concentration ,respiratory system ,Small intestine ,respiratory tract diseases ,Ractopamine ,Kinetics ,medicine.anatomical_structure ,Organ Specificity ,Isotope Labeling ,Salbutamol ,Sulfotransferases ,Sulfur ,medicine.drug - Abstract
Feed additives such as ractopamine and salbutamol are pharmacologically active compounds, acting primarily as β-adrenergic agonists. This study was designed to investigate whether the sulfation of ractopamine and salbutamol may occur under the metabolic conditions and to identify the human cytosolic sulfotransferases (SULTs) that are capable of sulfating two major feed additive compounds, ractopamine and salbutamol. A metabolic labelling study showed the generation and release of [(35)S]sulfated ractopamine and salbutamol by HepG2 human hepatoma cells labelled with [(35)S]sulfate in the presence of these two compounds. A systematic analysis using 11 purified human SULTs revealed SULT1A3 as the major SULT responsible for the sulfation of ractopamine and salbutamol. The pH dependence and kinetic parameters were analyzed. Moreover, the inhibitory effects of ractopamine and salbutamol on SULT1A3-mediated dopamine sulfation were investigated. Cytosol or S9 fractions of human lung, liver, kidney and small intestine were examined to verify the presence of ractopamine-/salbutamol-sulfating activity in vivo. Of the four human organs, the small intestine displayed the highest activity towards both compounds. Collectively, these results imply that the sulfation mediated by SULT1A3 may play an important role in the metabolism and detoxification of ractopamine and salbutamol.
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- 2012
7. Ethanol Sulfation by the Human Cytosolic Sulfotransferases: A Systematic Analysis
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Masahito Suiko, Garrett Davidson, Ming-Cheh Liu, Katsuhisa Kurogi, Yasir Ihsan Mohammed, Frederick E. Williams, Yoichi Sakakibara, and Ming-Yih Liu
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Adult ,Sulfotransferase ,Alcohol Drinking ,Pharmaceutical Science ,Sulfuric Acid Esters ,Ethyl sulfate ,chemistry.chemical_compound ,Cytosol ,Sulfation ,Intestine, Small ,medicine ,Humans ,Ethanol metabolism ,Lung ,Pharmacology ,chemistry.chemical_classification ,Ethanol ,Dose-Response Relationship, Drug ,Staining and Labeling ,Carbohydrate sulfotransferase ,Hep G2 Cells ,General Medicine ,Small intestine ,Enzyme ,medicine.anatomical_structure ,Liver ,chemistry ,Biochemistry ,Sulfotransferases ,Biomarkers - Abstract
Ethyl sulfate, a minor and direct ethanol metabolite in adult human body, has been implicated as a biomarker for alcohol consumption and in utero exposure to ethanol. To understand better the physiological relevance of the sulfation of ethanol, it is important to clarify the cytosolic sulfotransferase (SULT) enzymes that are responsible for ethanol sulfation. The present study aimed to identify the major ethanol-sulfating human SULTs and to investigate the sulfation of ethanol under the metabolic setting. A systematic analysis revealed four ethanol-sulfating SULTs, SULT1A1, SULT1A2, SULT1A3, and SULT1C4, among the eleven human SULT enzymes previously prepared and purified. A metabolic labeling study demonstrated the generation and release of ethyl [(35)S]sulfate in a concentration-dependent manner by HepG2 human hepatoma cells labeled with [(35)S]sulfate in the presence of different concentrations of ethanol. Cytosol or S9 fractions of human lung, liver, and small intestine were examined to verify the presence of ethanol-sulfating activity in vivo. Of the three human organs, the small intestine displayed the highest activity.
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- 2012
8. A comparative study of the sulfation of bile acids and a bile alcohol by the Zebra danio (Danio rerio) and human cytosolic sulfotransferases (SULTs)
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Ming-Cheh Liu, Matthew D. Krasowski, Yoichi Sakakibara, Ming-Yih Liu, Masahito Suiko, Elisha R. Injeti, Katsuhisa Kurogi, and Frederick E. Williams
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Sulfotransferase ,animal structures ,Lithocholic acid ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Kinetic analysis ,Danio ,digestive system ,Biochemistry ,Article ,Substrate Specificity ,Bile Acids and Salts ,chemistry.chemical_compound ,Cytosol ,Endocrinology ,Sulfation ,medicine ,Animals ,Humans ,Molecular Biology ,Zebrafish ,Bile acid ,biology ,Sulfates ,Cell Biology ,Hydrogen-Ion Concentration ,biology.organism_classification ,Kinetics ,chemistry ,Molecular Medicine ,Bile Alcohols ,Sulfotransferases ,Cholestanols - Abstract
The current study was designed to examine the sulfation of bile acids and bile alcohols by the Zebra danio (Danio rerio) SULTs in comparison with human SULTs. A systematic analysis using the fifteen Zebra danio SULTs revealed that SULT3 ST2 and SULT3 ST3 were the major bile acid/alcohol-sulfating SULTs. Among the eleven human SULTs, only SULT2A1 was found to be capable of sulfating bile acids and bile alcohols. To further investigate the sulfation of bile acids and bile alcohols by the two Zebra danio SULT3 STs and the human SULT2A1, pH-dependence and kinetics of the sulfation of bile acids/alcohols were analyzed. pH-dependence experiments showed that the mechanisms underlying substrate recognition for the sulfation of lithocholic acid (a bile acid) and 5α-petromyzonol (a bile alcohol) differed between the human SULT2A1 and the Zebra danio SULT3 ST2 and ST3. Kinetic analysis indicated that both the two Zebra danio SULT3 STs preferred petromyzonol as substrate compared to bile acids. In contrast, the human SULT2A1 was more catalytically efficient toward lithocholic acid than petromyzonol. Collectively, the results imply that the Zebra danio and human SULTs have evolved to serve for the sulfation of, respectively, bile alcohols and bile acids, matching the cholanoid profile in these two vertebrate species.
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- 2011
9. Crystallization of Adenylylsulfate Reductase from Desulfovibrio gigas: A Strategy Based on Controlled Protein Oligomerization
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Chun-Jung Chen, Vincent C.-C. Wang, Yen-Chieh Huang, Phimonphan Chuankhayan, Sunney I. Chan, Ming-Yih Liu, Ming-Chi Yang, Yuan-Lan Chiang, Yin-Cheng Hsieh, and Jou-Yin Fang
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chemistry.chemical_classification ,Adenosine monophosphate ,Stereochemistry ,General Chemistry ,Reductase ,Random hexamer ,Condensed Matter Physics ,Amino acid ,chemistry.chemical_compound ,Enzyme ,chemistry ,Biochemistry ,Dissimilatory sulfate reduction ,Desulfovibrio gigas ,Protein oligomerization ,General Materials Science - Abstract
Adenylylsulfate reductase (adenosine 5′-phosphosulfate reductase, APS reductase or APSR, E.C.1.8.99.2) catalyzes the conversion of APS to sulfite in dissimilatory sulfate reduction. APSR was isolated and purified directly from massive anaerobically grown Desulfovibrio gigas, a strict anaerobe, for structure and function investigation. Oligomerization of APSR to form dimers–α_2β_2, tetramers–α_4β_4, hexamers–α_6β_6, and larger oligomers was observed during purification of the protein. Dynamic light scattering and ultracentrifugation revealed that the addition of adenosine monophosphate (AMP) or adenosine 5′-phosphosulfate (APS) disrupts the oligomerization, indicating that AMP or APS binding to the APSR dissociates the inactive hexamers into functional dimers. Treatment of APSR with β-mercaptoethanol decreased the enzyme size from a hexamer to a dimer, probably by disrupting the disulfide Cys156—Cys162 toward the C-terminus of the β-subunit. Alignment of the APSR sequences from D. gigas and A. fulgidus revealed the largest differences in this region of the β-subunit, with the D. gigas APSR containing 16 additional amino acids with the Cys156—Cys162 disulfide. Studies in a pH gradient showed that the diameter of the APSR decreased progressively with acidic pH. To crystallize the APSR for structure determination, we optimized conditions to generate a homogeneous and stable form of APSR by combining dynamic light scattering, ultracentrifugation, and electron paramagnetic resonance methods to analyze the various oligomeric states of the enzyme in varied environments.
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- 2011
10. Identification, characterization, and ontogenic study of a catechol O-methyltransferase from zebrafish
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Yoichi Sakakibara, Frederick E. Williams, Katsuhisa Kurogi, Masahito Suiko, Adnan Alazizi, Ming-Yih Liu, and Ming-Cheh Liu
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animal structures ,Methyltransferase ,Health, Toxicology and Mutagenesis ,Molecular Sequence Data ,Catechols ,Gene Expression ,Aquatic Science ,Molecular cloning ,Biology ,Catechol O-Methyltransferase ,Methylation ,Polymerase Chain Reaction ,behavioral disciplines and activities ,Article ,Xenobiotics ,Complementary DNA ,mental disorders ,Gene expression ,Animals ,Cloning, Molecular ,Zebrafish ,Enzyme Assays ,Catechol-O-methyl transferase ,Expression vector ,Base Sequence ,fungi ,Gene Expression Regulation, Developmental ,Zebrafish Proteins ,biology.organism_classification ,Molecular biology ,Metabolic Detoxication, Phase II ,Biochemistry ,Models, Animal - Abstract
To establish the zebrafish as a model for investigating the methylation pathway of drug metabolism, we embarked on the molecular cloning of the zebrafish catechol O -methyltransferase (COMT). By searching the GenBank database, a zebrafish nucleotide sequence encoding a putative COMT was identified. Based on the sequence information, we designed and synthesized oligonucleotides corresponding to its 5′- and 3′-coding regions of this zebrafish COMT. Using the first-strand cDNA reverse-transcribed from the total RNA isolated from a 3-month-old adult female zebrafish as the template, the cDNA encoding the zebrafish COMT was PCR-amplified. The recombinant zebrafish COMT protein was subsequently expressed in and purified from BL21 (DE3) Escherichia coli cells transformed with the pGEX-2TK expression vector harboring the zebrafish COMT cDNA. Upon enzymatic characterization, purified COMT displayed methylating activity toward dopamine, dopa, and catecholestrogens, as well as three representative catechol drugs, methyldopa, dobutamine, and isoproterenol. A reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed developmental stage-dependent expression of the zebrafish COMT during embryonic development and throughout the larval stage onto maturity. These results provide a foundation for investigating the involvement of COMT-mediated methylation in protection against the adverse effects of catechol drugs and other xenobiotic catechols during the developmental process.
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- 2011
11. Structural insights into the enzyme catalysis from comparison of three forms of dissimilatory sulphite reductase from Desulfovibrio gigas
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En-Huang Liu, Yin-Cheng Hsieh, Sunney I. Chan, Yen-Lung Chiang, Vincent C.-C. Wang, Chun-Jung Chen, Ming-Yih Liu, and Wen-guey Wu
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Stereochemistry ,Substrate (chemistry) ,Crystal structure ,Biology ,Microbiology ,Sulfite reductase ,law.invention ,Enzyme catalysis ,chemistry.chemical_compound ,Thioether ,chemistry ,Biochemistry ,Covalent bond ,law ,Desulfovibrio gigas ,Electron paramagnetic resonance ,Molecular Biology - Abstract
The crystal structures of two active forms of dissimilatory sulphite reductase (Dsr) from Desulfovibrio gigas, Dsr-I and Dsr-II, are compared at 1.76 and 2.05 A resolution respectively. The dimeric α_2β_2γ_2 structure of Dsr-I contains eight [4Fe–4S] clusters, two saddle-shaped sirohaems and two flat sirohydrochlorins. In Dsr-II, the [4Fe–4S] cluster associated with the sirohaem in Dsr-I is replaced by a [3Fe–4S] cluster. Electron paramagnetic resonance (EPR) of the active Dsr-I and Dsr-II confirm the co-factor structures, whereas EPR of a third but inactive form, Dsr-III, suggests that the sirohaem has been demetallated in addition to its associated [4Fe–4S] cluster replaced by a [3Fe–4S] centre. In Dsr-I and Dsr-II, the sirohydrochlorin is located in a putative substrate channel connected to the sirohaem. The γ-subunit C-terminus is inserted into a positively charged channel formed between the α- and β-subunits, with its conserved terminal Cysγ104 side-chain covalently linked to the CHA atom of the sirohaem in Dsr-I. In Dsr-II, the thioether bond is broken, and the Cysγ104 side-chain moves closer to the bound sulphite at the sirohaem pocket. These different forms of Dsr offer structural insights into a mechanism of sulphite reduction that can lead to S_3O_6^(2−), S_2O_3^(2−) and S^(2−).
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- 2010
12. Zebrafish as a Model for the Study of the Phase II Cytosolic Sulfotransferases
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Shakhawat Bhuiyan, Masahito Suiko, Takuya Sugahara, Ming Yih Liu, Frederick E. Williams, Tzu An Liu, Yoichi Sakakibara, Ming-Cheh Liu, Makoto Kimura, Shin Yasuda, and Yoshimitsu Kakuta
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Pharmacology ,chemistry.chemical_classification ,Molecular Sequence Data ,Clinical Biochemistry ,Biology ,biology.organism_classification ,chemistry.chemical_compound ,Cytosol ,Enzyme ,chemistry ,Biochemistry ,Multigene Family ,Detoxification ,Models, Animal ,Animals ,Humans ,Gene family ,Amino Acid Sequence ,Sulfotransferases ,Xenobiotic ,Peptide sequence ,Zebrafish ,Drug metabolism - Abstract
Cytosolic sulfotransferases (SULTs) are traditionally known as the Phase II drug-metabolizing or detoxifying enzymes that serve for the detoxification of drugs and other xenobiotics. These enzymes in general catalyze the transfer of a sulfonate group from the active sulfate, 3'-phosphoadenosine 5'-phosphosulfate (PAPS), to low-molecular weight substrate compounds containing hydroxyl or amino group(s). Despite considerable efforts made in recent years, some fundamental aspects of the SULTs, particularly their ontogeny, cell type/tissue/organ-specific distribution, and physiological relevance, particularly their involvement in drug metabolism and detoxification, still remain poorly understood. To better understand these fundamental issues, we have embarked on developing the zebrafish as a model for studies concerning the SULTs. To date, fifteen zebrafish SULTs have been cloned, expressed, purified, and characterized. These zebrafish SULTs, which fall into four major SULT gene families, exhibited differential substrate specificities and distinct patterns of expression at different stages during embryogenesis, through larval development, and on to maturity. The information obtained, as summarized in this review, provides a foundation for further investigation into the physiological and pharmacological involvement of the SULTs using the zebrafish as a model.
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- 2010
13. Crystal structures of SULT1A2 and SULT1A1∗3: Insights into the substrate inhibition and the role of Tyr149 in SULT1A2
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Mei Li, Haitao Li, Jing-Hua Lu, Ming-Cheh Liu, Xiao-Min An, Ming-Yih Liu, Jiping Zhang, and Wenrui Chang
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Protein Conformation ,Stereochemistry ,medicine.medical_treatment ,Phosphoadenosine Phosphosulfate ,Mutant ,Biophysics ,Crystallography, X-Ray ,Biochemistry ,Catalysis ,Substrate Specificity ,Steroid ,Nitrophenols ,chemistry.chemical_compound ,Residue (chemistry) ,medicine ,Humans ,Molecular Biology ,Chemistry ,Mutagenesis ,Substrate (chemistry) ,Cell Biology ,Arylsulfotransferase ,Cytosol ,Sulfonate ,Mutation ,Mutagenesis, Site-Directed ,Tyrosine ,Selectivity - Abstract
The cytosolic sulfotransferases (SULTs) in vertebrates catalyze the sulfonation of endogenous thyroid/steroid hormones and catecholamine neurotransmitters, as well as a variety of xenobiotics, using 3′-phosphoadenosine 5′-phosphosulfate (PAPS) as the sulfonate donor. In this study, we determined the structures of SULT1A2 and an allozyme of SULT1A1, SULT1A1∗3, bound with 3′-phosphoadenosine 5′-phosphate (PAP), at 2.4 and 2.3 A resolution, respectively. The conformational differences between the two structures revealed a plastic substrate-binding pocket with two channels and a switch-like substrate selectivity residue Phe247, providing clearly a structural basis for the substrate inhibition. In SULT1A2, Tyr149 extends approximately 2.1 A further to the inside of the substrate-binding pocket, compared with the corresponding His149 residue in SULT1A1∗3. Site-directed mutagenesis study showed that, compared with the wild-type SULT1A2, mutant Tyr149Phe SULT1A2 exhibited a 40 times higher Km and two times lower Vmax with p-nitrophenol as substrate. These latter data imply a significant role of Tyr149 in the catalytic mechanism of SULT1A2.
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- 2010
14. Sulfation of Drug Compounds by the Zebrafish Cytosolic Sulfotransferases (SULTs)
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Yoichi Sakakibara, Masahito Suiko, Katsuhisa Kurogi, Ming-Cheh Liu, Frederick E. Williams, Ahmed Nasser, Ming-Yih Liu, and Jeremiah Dillon
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Drug ,media_common.quotation_subject ,Clinical Biochemistry ,Pharmaceutical Science ,Biology ,law.invention ,Cytosol ,Sulfation ,law ,Cell Line, Tumor ,Animals ,Humans ,Pharmacology (medical) ,Zebrafish ,media_common ,chemistry.chemical_classification ,Sulfates ,Biochemistry (medical) ,biology.organism_classification ,Recombinant Proteins ,Kinetics ,Enzyme ,Pharmaceutical Preparations ,chemistry ,Biochemistry ,Cell culture ,Hepatocytes ,Recombinant DNA ,Sulfotransferases ,Drug metabolism - Abstract
To establish the zebrafish as a model to investigate drug metabolism through sulfation, we had previous cloned, expressed, and purified fourteen distinct zebrafish cytosolic sulfotransferases (SULTs). In the present study, we carried a systematic analysis of the sulfating activities of these fourteen zebrafish SULTs toward a panel of drug compounds. Results showed that four of the fourteen zebrafish SULTs showed no detectable activities toward any of the tested drugs. Among the other ten zebrafish SULTs, three SULT1 enzymes (SULT1 ST1, SULT1 ST2, and SULT1 ST3) displayed considerably stronger activities than the others toward the majority of the drug compounds tested. Specifically, SULT1 ST1, SULT1 ST2, and SULT1 ST3 showed the highest specific activities, at 26.9, 29.3, and 31.5 nmol/min/mg, toward aesculetin, 4-methylembelliferone, and dobutamine, respectively. To further investigate the sulfation of tested drugs by the responsible zebrafish SULT enzymes, the kinetics of the sulfation reactions were analyzed. Kinetic constants determined indicated that the sulfation of these drugs by the SULT enzymes tested is likely to be physiologically relevant. A metabolic labeling experiment using cultured zebrafish liver cells and HepG2 human hepatoma cells was performed. Results showed that zebrafish liver cells displayed a similar pattern of sulfation of the drugs tested as that of HepG2 cells, implying that human and zebrafish liver cells may share considerable similarities with regard to their constituent drug-sulfating SULT enzymes.
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- 2010
15. Inhibitory Effects of Nitrative Stress on the Sulfation of 17.BETA.-Estradiol and 4-Methoxyestradiol by Human MCF 10A Mammary Epithelial Cells
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Tomoko Yasuda, Yoichi Sakakibara, Ming-Yih Liu, Katherine A. Wall, Shin Yasuda, Masahito Suiko, Ying Hui, and Ming-Cheh Liu
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medicine.medical_specialty ,Sulfotransferase ,4-Methoxyestradiol ,medicine.drug_class ,Pharmaceutical Science ,medicine.disease_cause ,Cell Line ,Nitric oxide ,chemistry.chemical_compound ,Sulfation ,Internal medicine ,medicine ,Humans ,Nitric Oxide Donors ,Tyrosine ,Mammary Glands, Human ,Pharmacology ,Dose-Response Relationship, Drug ,Estradiol ,Chemistry ,Epithelial Cells ,General Medicine ,Nitro Compounds ,Oxidative Stress ,Endocrinology ,Estrogen ,Cell culture ,Sulfotransferases ,Oxidative stress - Abstract
Prolonged exposure to high level of estrogen is a known risk factor for breast carcinogenesis. It has been suggested recently that nitrative stress may be an etiologic factor for breast carcinogenesis. Since sulfation plays a major role in the homeostasis of estrogens and their metabolites, we attempted in the present study to find out whether nitrative stress may affect the homeostasis of estrogens through sulfation. Metabolic labeling experiments revealed that the amount of sulfated 17beta-estradiol or 4-methoxyestradiol decreased dramatically in MCF-10A mammary epithelial cells incubated in the presence of 3-morpholinosydnonimine (SIN-1) or diethylenetriamine NONOate (DETA NONOate), two nitric oxide donors commonly used to simulate nitrative stress conditions. In searching for the mechanism underlying the decrease of the sulfation of 17beta-estradiol and 4-methoxyestradiol, we demonstrated in an in vitro nitration experiment, that the human cytosolic sulfotransferase isoform 1E1 (SULT1E1), a major estrogen-sulfating enzyme, lost its estrogen-sulfating activity proportionately to the degree of nitration on tyrosine residues. Moreover, cell lysates prepared from MCF-10A cells treated with SIN-1 or DETA NONOate also showed much lower 4-methoxyestradiol-sulfating activities, compared with those determined with cell lysate prepared from control MCF-10A cells.
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- 2010
16. Crystal Structure of Adenylylsulfate Reductase from Desulfovibrio gigas Suggests a Potential Self-Regulation Mechanism Involving the C Terminus of the β-Subunit
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En-Hong Liu, Jeyaraman Jeyakanthan, Ming-Yih Liu, Chun-Jung Chen, Phimonphan Chuankhayan, Yuan-Lan Chiang, Jou-Yin Fang, Sunney I. Chan, Yen-Chieh Huang, and Yin-Cheng Hsieh
- Subjects
Models, Molecular ,Stereochemistry ,Molecular Sequence Data ,Sequence alignment ,Random hexamer ,Crystallography, X-Ray ,Spectrum Analysis, Raman ,Microbiology ,chemistry.chemical_compound ,Structural Biology ,Desulfovibrio gigas ,Oxidoreductases Acting on Sulfur Group Donors ,Amino Acid Sequence ,Protein Structure, Quaternary ,Molecular Biology ,Peptide sequence ,Flavin adenine dinucleotide ,biology ,C-terminus ,Archaeoglobus fulgidus ,Active site ,Social Control, Informal ,Adenosine Monophosphate ,Protein Subunits ,chemistry ,Biochemistry ,Flavin-Adenine Dinucleotide ,biology.protein ,Sequence Alignment ,Ultracentrifugation ,Protein Binding - Abstract
Adenylylsulfate reductase (adenosine 5′-phosphosulfate [APS] reductase [APSR]) plays a key role in catalyzing APS to sulfite in dissimilatory sulfate reduction. Here, we report the crystal structure of APSR from Desulfovibrio gigas at 3.1-Å resolution. Different from the α 2 β 2 -heterotetramer of the Archaeoglobus fulgidus , the overall structure of APSR from D. gigas comprises six αβ-heterodimers that form a hexameric structure. The flavin adenine dinucleotide is noncovalently attached to the α-subunit, and two [4Fe-4S] clusters are enveloped by cluster-binding motifs. The substrate-binding channel in D. gigas is wider than that in A. fulgidus because of shifts in the loop (amino acid 326 to 332) and the α-helix (amino acid 289 to 299) in the α-subunit. The positively charged residue Arg160 in the structure of D. gigas likely replaces the role of Arg83 in that of A. fulgidus for the recognition of substrates. The C-terminal segment of the β-subunit wraps around the α-subunit to form a functional unit, with the C-terminal loop inserted into the active-site channel of the α-subunit from another αβ-heterodimer. Electrostatic interactions between the substrate-binding residue Arg282 in the α-subunit and Asp159 in the C terminus of the β-subunit affect the binding of the substrate. Alignment of APSR sequences from D. gigas and A. fulgidus shows the largest differences toward the C termini of the β-subunits, and structural comparison reveals notable differences at the C termini, activity sites, and other regions. The disulfide comprising Cys156 to Cys162 stabilizes the C-terminal loop of the β-subunit and is crucial for oligomerization. Dynamic light scattering and ultracentrifugation measurements reveal multiple forms of APSR upon the addition of AMP, indicating that AMP binding dissociates the inactive hexamer into functional dimers, presumably by switching the C terminus of the β-subunit away from the active site. The crystal structure of APSR, together with its oligomerization properties, suggests that APSR from sulfate-reducing bacteria might self-regulate its activity through the C terminus of the β-subunit.
- Published
- 2009
17. Concerted action of the cytosolic sulfotransferase, SULT1A3, and catechol-O-methyltransferase in the metabolism of dopamine in SK-N-MC human neuroblastoma cells
- Author
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Ming-Yih Liu, Shin Yasuda, Ming-Cheh Liu, Ying Hui, Masahito Suiko, Tomoko Yasuda, and Yoichi Sakakibara
- Subjects
Sulfotransferase ,Dopamine ,Catechol O-Methyltransferase ,COMT inhibitor ,Methylation ,Tropolone ,Cell Line ,Substrate Specificity ,chemistry.chemical_compound ,Cytosol ,Sulfation ,medicine ,Homeostasis ,Humans ,Neurons ,Catechol-O-methyl transferase ,Sulfates ,Chemistry ,General Neuroscience ,Dopaminergic ,Catechol O-Methyltransferase Inhibitors ,General Medicine ,Arylsulfotransferase ,Deoxyepinephrine ,Monoamine neurotransmitter ,Biochemistry ,Isotope Labeling ,Sulfotransferases ,Protein Processing, Post-Translational ,medicine.drug - Abstract
Conjugation reactions catalyzed by the cytosolic sulfotransferase, SULT1A3, or catechol- O -methyltransferase (COMT) are known to be involved in the regulation and homeostasis of dopamine and other monoamine neurotransmitters. Whether different conjugation reactions may act in a concerted manner, however, remains unclear. The current study aimed to investigate the concerted action of SULT1A3 and COMT in dopamine metabolism. Analysis of the medium of SK-N-MC cells, metabolically labeled with [ 35 S]sulfate in the presence of dopamine, revealed the generation and release of predominantly [ 35 S]sulfated 3-methyldopamine and, to a lesser extent [ 35 S]sulfated dopamine. Addition to the labeling medium of tropolone, a COMT inhibitor, enhanced the production of [ 35 S]sulfated dopamine, with a concomitant decrease of [ 35 S]sulfated 3-methyldopamine. Enzymatic assays using the eleven known human cytosolic SULTs revealed SULT1A3 as the major enzyme responsible for the sulfation of both dopamine and 3-methyldopamine. Kinetic analysis showed that the catalytic efficiency of SULT1A3 with 3-methyldopamine was 1.6 times than that with dopamine. Using subcellular fractions prepared from SK-N-MC cells, the majority of COMT dopamine-methylating activity was found to be present in the cytosol. Collectively, these results imply a concerted action of sulfation and methylation in the irreversible inactivation and disposal of excess dopamine in SK-N-MC cells.
- Published
- 2009
18. Characterization and ontogenic study of novel steroid-sulfating SULT3 sulfotransferases from zebrafish
- Author
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Ming-Cheh Liu, Glendora Carter, Yoichi Sakakibara, Tomoko Yasuda, Frederick E. Williams, Shakhawat Bhuiyan, Shin Yasuda, Rhodora Snow, and Ming-Yih Liu
- Subjects
Sulfotransferase ,Molecular Sequence Data ,Dehydroepiandrosterone ,Biology ,Biochemistry ,Substrate Specificity ,Xenobiotics ,law.invention ,Cytosol ,Endocrinology ,Sulfation ,law ,Complementary DNA ,Animals ,Amino Acid Sequence ,Cloning, Molecular ,Molecular Biology ,Zebrafish ,Phylogeny ,chemistry.chemical_classification ,Expression vector ,Sulfates ,Gene Expression Regulation, Developmental ,Hydrogen-Ion Concentration ,biology.organism_classification ,Recombinant Proteins ,Kinetics ,Enzyme ,chemistry ,Recombinant DNA ,Steroids ,Sulfotransferases - Abstract
In vertebrates, sulfation as catalyzed by members of the cytosolic sulfotransferase (SULT) family has been suggested to be involved in the homeostasis of steroids. To establish the zebrafish as a model for investigating how sulfation functions to regulate steroid metabolism during the developmental process, we have embarked on the identification of steroid-sulfating SULTs in zebrafish. By searching the GenBank database, we identified two putative cytosolic SULT sequences from zebrafish, designated SULT3 ST1 and ST2. The recombinant proteins of these two zebrafish SULT3 STs were expressed in and purified from BL21 (DE3) cells transformed with the pGEX-2TK expression vector harboring SULT3 ST1 or ST2 cDNA. Upon enzymatic characterization, purified SULT3 ST1 displayed the strongest sulfating activity toward 17beta-estradiol among the endogenous substrates tested, while SULT3 ST2 exhibited substrate specificity toward hydroxysteroids, particularly dehydroepiandrosterone (DHEA). The pH-dependence and kinetic constants of these two enzymes with 17beta-estradiol and DHEA were determined. A developmental expression study revealed distinct patterns of the expression of SULT3 ST1 and ST2 during embryonic development and throughout the larval stage onto maturity. Collectively, these results imply that these two steroid-sulfating SULT3 STs may play differential roles in the metabolism and regulation of steroids during zebrafish development and in adulthood.
- Published
- 2008
19. Rational Design for Crystallization of β-Lactoglobulin and Vitamin D3 Complex: Revealing a Secondary Binding Site
- Author
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Ming Yih Liu, Cheng Neng Ko, Simon J.T. Mao, Yen-Chieh Huang, Ming Chi Yang, Jinn-Moon Yang, Hong Hsiang Guan, Yih Hung Lin, and Chun-Jung Chen
- Subjects
Vitamin ,Whey protein ,Rational design ,General Chemistry ,Condensed Matter Physics ,Cocrystal ,Fluorescence ,Calyx ,chemistry.chemical_compound ,Vitamin D binding ,Biochemistry ,chemistry ,General Materials Science ,Binding site - Abstract
β-Lactoglobulin (LG) is a major milk whey protein containing primarily a calyx for vitamin D3 binding, although the existence of another site beyond the calyx is controversial. Using fluorescence spectral analyses in the previous study, we showed the binding stoichiometry for vitamin D3 to LG to be 2:1 and a stoichiometry of 1:1 when the calyx was “disrupted” by manipulating the pH and temperature, suggesting that a secondary vitamin D binding site existed. To help localize this secondary site using X-ray crystallography in the present study, we used bioinformatic programs (Insight II, Q-SiteFinder, and GEMDOCK) to identify the potential location of this site. We then optimized the occupancy and enhanced the electron density of vitamin D3 in the complex by altering the pH and initial ratios of vitamin D3/LG in the cocrystal preparation. We conclude that GEMDOCK can aid in searching for an extra density map around potential vitamin D binding sites. Both pH (8) and initial ratio of vitamin D3/LG (3:1) are c...
- Published
- 2008
20. On the Sulfation and Methylation of Catecholestrogens in Human Mammary Epithelial Cells and Breast Cancer Cells
- Author
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Ming-Yih Liu, Ming-Cheh Liu, Yi-yong Wu, Ying Hui, and Shin Yasuda
- Subjects
Sulfotransferase ,medicine.drug_class ,Catechols ,Pharmaceutical Science ,Breast Neoplasms ,Estrone ,Biology ,Catechol O-Methyltransferase ,Sulfur Radioisotopes ,medicine.disease_cause ,Methylation ,Tropolone ,chemistry.chemical_compound ,Cytosol ,Sulfation ,Cell Line, Tumor ,medicine ,Humans ,Breast ,Pharmacology ,chemistry.chemical_classification ,Catechol-O-methyl transferase ,Sulfates ,Epithelial Cells ,Estrogens ,General Medicine ,Recombinant Proteins ,Enzyme ,chemistry ,Biochemistry ,Estrogen ,Female ,Sulfotransferases ,Carcinogenesis - Abstract
Prolonged exposure to high level of estrogen is a known risk factor for breast carcinogenesis. In cells, estrogens, in particular estrone (E1) and 17 beta-estradiol (E2), can be converted to catecholestrogens (CEs) which may be oxidized to form CE-semiquinones and CE-quinones that are capable of binding to DNA to induce mutations, followed by carcinogenesis. Whether the body is equipped with protective mechanisms against potentially harmful CEs, therefore, is an important issue. The present study was designed to examine the role of sulfation in the metabolism of CEs. MCF-7 breast cancer cells and MCF 10A human mammary epithelial cells were metabolically labeled with [35S]sulfate in the presence of individual CEs. Analysis of the labeling media showed the generation and release of exclusively [35S]sulfated 2-methoxy-E1 or [35S]sulfated 2- or 4-methoxy-E2 by cells labeled in the presence of 2-OH-E1 or 2- or 4-OH-E2. Whereas both [35S]sulfated 4-methoxy-E1 and [35S]sulfated 4-OH-E1 were detected in the labeling media of cells labeled in the presence of 4-OH-E1. These results indicated a concerted action of catechol-O-methyltransferase (COMT) and the cytosolic sulfotransferase (SULT) enzyme(s) in the metabolism of CEs. Enzymatic assays revealed that, five (SULT1A1, SULT1A2, SULT1A3, SULT1C4, and SULT1E1) of eleven known human SULTs tested could use CEs and methoxyestrogens (MEs) as substrates, with SULT1E1 displaying the strongest sulfating activity.
- Published
- 2008
21. Sulfation of benzyl alcohol by the human cytosolic sulfotransferases (SULTs): a systematic analysis
- Author
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Lingtian, Zhang, Katsuhisa, Kurogi, Ming-Yih, Liu, Alaina M, Schnapp, Frederick E, Williams, Yoichi, Sakakibara, Masahito, Suiko, and Ming-Cheh, Liu
- Subjects
Sulfates ,organic chemicals ,Hep G2 Cells ,Kidney ,Arylsulfotransferase ,Article ,Cytosol ,Liver ,Intestine, Small ,Humans ,heterocyclic compounds ,Caco-2 Cells ,Lung ,Benzyl Alcohol - Abstract
The aim of the present study was to identify human cytosolic sulfotransferases (SULTs) that are capable of sulfating benzyl alcohol and to examine whether benzyl alcohol sulfation may occur in cultured human cells as well as in human organ homogenates. A systematic analysis revealed that of the 13 known human SULTs, SULT1A1 SULT1A2, SULTA3, and SULT1B1 are capable of mediating the sulfation of benzyl alcohol. The kinetic parameters of SULT1A1 that showed the strongest benzyl alcohol-sulfating activity were determined. HepG2 human hepatoma cells were used to demonstrate the generation and release of sulfated benzyl alcohol under the metabolic settings. Moreover, the cytosol or S9 fractions of human liver, lung, kidney and small intestine were examined to verify the presence of benzyl alcohol sulfating activity in vivo. Copyright © 2015 John WileySons, Ltd.
- Published
- 2015
22. Sulphation of acetaminophen by the human cytosolic sulfotransferases: a systematic analysis
- Author
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Akihiro Yamamoto, Ming-Yih Liu, Katsuhisa Kurogi, Ming-Cheh Liu, Yoichi Sakakibara, Yuichi Saeki, and Masahito Suiko
- Subjects
Sulfotransferase ,Kidney ,Biochemistry ,digestive system ,Sulfation ,Cytosol ,In vivo ,medicine ,Humans ,Molecular Biology ,Lung ,Acetaminophen ,chemistry.chemical_classification ,organic chemicals ,digestive, oral, and skin physiology ,Regular Papers ,General Medicine ,Metabolism ,Hep G2 Cells ,Analgesics, Non-Narcotic ,Hydrogen-Ion Concentration ,Arylsulfotransferase ,digestive system diseases ,Intestines ,stomatognathic diseases ,Kinetics ,Enzyme ,medicine.anatomical_structure ,chemistry ,Liver ,Biocatalysis ,Caco-2 Cells ,Sulfotransferases ,medicine.drug - Abstract
Sulphation is known to be critically involved in the metabolism of acetaminophen in vivo. This study aimed to systematically identify the major human cytosolic sulfotransferase (SULT) enzyme(s) responsible for the sulphation of acetaminophen. A systematic analysis showed that three of the twelve human SULTs, SULT1A1, SULT1A3 and SULT1C4, displayed the strongest sulphating activity towards acetaminophen. The pH dependence of the sulphation of acetaminophen by each of these three SULTs was examined. Kinetic parameters of these three SULTs in catalysing acetaminophen sulphation were determined. Moreover, sulphation of acetaminophen was shown to occur in HepG2 human hepatoma cells and Caco-2 human intestinal epithelial cells under the metabolic setting. Of the four human organ samples tested, liver and intestine cytosols displayed considerably higher acetaminophen-sulphating activity than those of lung and kidney. Collectively, these results provided useful information concerning the biochemical basis underlying the metabolism of acetaminophen in vivo previously reported.
- Published
- 2015
23. Identification of novel hydroxysteroid-sulfating cytosolic SULTs, SULT2 ST2 and SULT2 ST3, from zebrafish: Cloning, expression, characterization, and developmental expression
- Author
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Saki Takahashi, Rhodora Snow, Yuh-Shyong Yang, Shin Yasuda, Ming Cheh Liu, and Ming Yih Liu
- Subjects
Male ,Sulfotransferase ,DNA, Complementary ,Sequence analysis ,Molecular Sequence Data ,Biophysics ,Molecular cloning ,Biology ,Biochemistry ,Gene Expression Regulation, Enzymologic ,Fusion gene ,chemistry.chemical_compound ,Cytosol ,Animals ,Gene family ,Amino Acid Sequence ,RNA, Messenger ,Cloning, Molecular ,Molecular Biology ,Zebrafish ,Hydroxysteroids ,Phylogeny ,Expressed sequence tag ,Sequence Homology, Amino Acid ,Reverse Transcriptase Polymerase Chain Reaction ,Sulfates ,Gene Expression Regulation, Developmental ,Dehydroepiandrosterone ,Sequence Analysis, DNA ,Hydrogen-Ion Concentration ,Zebrafish Proteins ,biology.organism_classification ,Molecular biology ,Recombinant Proteins ,Isoenzymes ,chemistry ,Electrophoresis, Polyacrylamide Gel ,Female ,Hydroxysteroid ,Sulfotransferases ,Corticosterone - Abstract
By searching the expressed sequence tag database, two zebrafish cDNAs encoding putative cytosolic sulfotransferases (SULTs) were identified. Sequence analysis indicated that these two zebrafish SULTs belong to the cytosolic SULT2 gene family. The recombinant form of these two novel zebrafish SULTs, designated SULT2 ST2 and SULT2 ST3, were expressed using the pGEX-2TK glutathione S-transferase (GST) gene fusion system and purified from transformed BL21 (DE3) Escherichia coli cells. Purified GST-fusion protein form of SULT2 ST2 and SULT2 ST3 exhibited strong sulfating activities toward dehydroepiandrosterone (DHEA) and corticosterone, respectively, among various endogenous compounds tested as substrates. Both enzymes displayed pH optima at approximately 6.5. Kinetic constants of the two enzymes, as well as the GST-fusion protein form of the previously identified SULT2 ST1, with DHEA and corticosterone as substrates were determined. Developmental stage-dependent expression experiments revealed distinct patterns of expression of SULT2 ST2 and SULT2 ST3, as well as the previously identified SULT2 ST1, during embryonic development and throughout the larval stage onto maturity.
- Published
- 2006
24. Crystal structure of rubredoxin from Desulfovibrio gigas to ultra-high 0.68Å resolution
- Author
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Ming-Yih Liu, Chun-Jung Chen, Yen-Chieh Huang, and Yi Hung Lin
- Subjects
Models, Molecular ,Protein Folding ,Protein Conformation ,Iron ,Molecular Conformation ,Biophysics ,Crystallography, X-Ray ,Biochemistry ,Electron Transport ,Electron transfer ,Oxidoreductase ,Rubredoxin ,Metalloprotein ,Desulfovibrio gigas ,Molecular Biology ,chemistry.chemical_classification ,biology ,Rubredoxins ,Temperature ,Hydrogen Bonding ,Cell Biology ,biology.organism_classification ,Electron transport chain ,Desulfovibrio ,Crystallography ,Models, Chemical ,chemistry ,Solvents ,Anaerobic bacteria ,Oxidation-Reduction - Abstract
Rubredoxin ( D . g . Rd) is a small non-heme iron–sulfur protein shown to function as a redox coupling protein from the sulfate reducing bacteria Desulfovibrio gigas . The protein is generally purified from anaerobic bacteria in which it is thought to be involved in electron transfer or exchange processes. Rd transfers an electron to oxygen to form water as part of a unique electron transfer chain, composed by NADH:rubredoxin oxidoreductase (NRO), rubredoxin and rubredoxin:oxygen oxidoreductase (ROO) in D . g . The crystal structure of D . g . Rd has been determined by means of both a Fe single-wavelength anomalous dispersion (SAD) signal and the direct method, and refined to an ultra-high 0.68 A resolution, using X-ray from a synchrotron. Rd contains one iron atom bound in a tetrahedral coordination by the sulfur atoms of four cysteinyl residues. Hydrophobic and π–π interactions maintain the internal Rd folding. Multiple conformations of the iron–sulfur cluster and amino acid residues are observed and indicate its unique mechanism of electron transfer. Several hydrogen bonds, including N H⋯SG of the iron–sulfur, are revealed clearly in maps of electron density. Abundant waters bound to C O peptides of residues Val8, Cys9, Gly10, Ala38, and Gly43, which may be involved in electron transfer. This ultrahigh-resolution structure allows us to study in great detail the relationship between structure and function of rubredoxin, such as salt bridges, hydrogen bonds, water structures, cysteine ligands, iron–sulfur cluster, and distributions of electron density among activity sites. For the first time, this information will provide a clear role for this protein in a strict anaerobic bacterium.
- Published
- 2006
25. Identification of a novel thyroid hormone-sulfating cytosolic sulfotransferase, SULT1 ST5, from zebrafish
- Author
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Lanzhuang Chen, Yoichi Sakakibara, Ming-Cheh Liu, Masahito Suiko, Shin Yasuda, Ming-Yih Liu, and Amit Kumar
- Subjects
chemistry.chemical_classification ,Sulfotransferase ,biology ,Thyroid ,Cell Biology ,biology.organism_classification ,Biochemistry ,Molecular biology ,Cytosol ,medicine.anatomical_structure ,Enzyme ,chemistry ,Complementary DNA ,medicine ,Molecular Biology ,Zebrafish ,Peptide sequence ,Hormone - Abstract
By employing RT-PCR in conjunction with 3'-RACE, a full-length cDNA encoding a novel zebrafish cytosolic sulfotransferase (SULT) was cloned and sequenced. Sequence analysis revealed that this zebrafish SULT (designated SULT1 ST5) is, at the amino acid sequence level, close to 50% identical to human and dog SULT1B1 (thyroid hormone SULT). A recombinant form of zebrafish SULT1 ST5 was expressed using the pGEX-2TK bacterial expression system and purified from transformed BL21 (DE3) cells. Purified zebrafish SULT1 ST5 migrated as a 34 kDa protein and displayed substrate specificity for thyroid hormones and their metabolites among various endogenous compounds tested. The enzyme also exhibited sulfating activities toward some xenobiotic phenolic compounds. Its pH optima were 6.0 and 9.0 with 3,3',5-triiodo-l-thyronine (l-T3) as substrate and 6.0 with beta-naphthol as substrate. Kinetic constants of the enzyme with thyroid hormones and their metabolites as substrates were determined. Quantitative evaluation of the regulatory effects of divalent metal cations on the l-T3-sulfating activity of SULT1 ST5 revealed that Fe2+, Hg2+, Co2+, Zn2+, Cu2+, Cd2+ and Pb2+ exhibited dramatic inhibitory effects, whereas Mn2+ showed a significant stimulation. Developmental stage-dependent expression experiments revealed a significant level of expression of this novel zebrafish thyroid hormone-sulfating SULT at the beginning of the hatching period during embryogenesis, which gradually increased to a high level of expression throughout the larval stage into maturity.
- Published
- 2005
26. Anaerobic purification and crystallization to improve the crystal quality: ferredoxin II from Desulfovibrio gigas
- Author
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Jean Le Gall, Ying-Cheng Hsieh, Ming-Yih Liu, and Chun-Jung Chen
- Subjects
chemistry.chemical_classification ,biology ,Stereochemistry ,General Medicine ,Crystallography, X-Ray ,biology.organism_classification ,law.invention ,Amino acid ,Enzyme ,chemistry ,Structural Biology ,law ,Ferredoxins ,Degradation (geology) ,Desulfovibrio gigas ,Crystallization ,Anaerobic exercise ,Function (biology) ,Bacteria - Abstract
Sulfate-reducing bacteria (SRB), which are strict anaerobes, contain an electron-transfer chain from pyridine nucleotides to molecular oxygen. This unique enzymatic equipment allows the bacterium to produce ATP when exposed to air from the degradation of internal reserves of polyglucose. Ferredoxin II (Fd II) is a small electron-transfer protein isolated from the strict anaerobic sulfate-reducing bacterium Desulfovibrio gigas. The protein contains 58 amino acids and an iron–sulfur cluster. The cluster [3Fe–4S] spontaneously undergoes conversion to [4Fe–4S] when it is used as an electron mediator in the phosphoroclastic reaction. The iron–sulfur geometries and interconversion mechanism appear to have physiological significance between the oxidized and reduced states. Crystallization of Fd II in an anaerobic environment was achieved at a higher resolution of 1.37 Å and the differences between the anaerobic and aerobic structures will reveal the unique iron-storage function and electron-transfer mechanism of ferredoxin II from D. gigas.
- Published
- 2005
27. Identification of a novel zebrafish SULT1 cytosolic sulfotransferase: Cloning, expression, characterization, and developmental expression study
- Author
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Ming-Cheh Liu, Shin Yasuda, Takuya Sugahara, Ming Yih Liu, and Yuh-Shyong Yang
- Subjects
Gene isoform ,Sulfotransferase ,Molecular Sequence Data ,Biophysics ,Gene Expression ,Molecular cloning ,Biochemistry ,Mice ,Complementary DNA ,Animals ,Humans ,Amino Acid Sequence ,Cloning, Molecular ,Molecular Biology ,Peptide sequence ,Zebrafish ,Phylogeny ,Gel electrophoresis ,Expressed sequence tag ,Sequence Homology, Amino Acid ,biology ,Zebrafish Proteins ,biology.organism_classification ,Arylsulfotransferase ,Molecular biology ,Isoenzymes - Abstract
By searching the zebrafish expressed sequence tag database, we had identified two partial cDNA clones encoding the 5′- and 3′-regions of a putative cytosolic sulfotransferase (SULT). Using the reverse transcription-polymerase chain reaction (RT-PCR) technique, a full-length cDNA encoding this zebrafish SULT was amplified, cloned, and sequenced. Analysis of the sequence data revealed that this novel zebrafish SULT displays 49, 46, and 45% amino acid sequence identity to human SULT1A1, mouse SULT1D1, and rat SULT1C1. This zebrafish SULT therefore appears to belong to the SULT1 cytosolic SULT gene family. Recombinant zebrafish SULT (designated SULT1 isoform 4), expressed using the pGEX-2TK prokaryotic expression vector and purified from transformed Escherichia coli cells, migrated as a 35 kDa protein upon sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Among the endogenous compounds tested as substrates, the purified SULT1 isoform 4 displayed significant sulfating activities toward thyroid hormones, estrone, and dehydroepiandrosterone. The enzyme also showed activities toward a number of xenobiotics including some flavonoids, isoflavonoids, and other phenolic compounds, with a pH optimum at 7.0. A thermostability experiment revealed the enzyme to be relatively stable over a temperature range between 28 and 37 °C. Among 10 divalent metal cations tested, Fe2+, Hg2+, Co2+, Zn2+, Cu2+, and Cd2+ exhibited dramatic inhibitory effects on the activity of the enzyme. Developmental expression study using RT-PCR revealed that the zebrafish SULT1 isoform 4 showed a low level of expression in the segmentation period during the embryonic development, which gradually increased to a high level of expression throughout the larval stage onto maturity.
- Published
- 2005
28. Cytosolic Sulfotransferases and Environmental Estrogenic Chemicals
- Author
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Masahito Suiko, Ming-Cheh Liu, Yoichi Sakakibara, Ming Yih Liu, and Yuh-Shyong Yang
- Subjects
Sulfotransferase ,Chemical compound ,Health, Toxicology and Mutagenesis ,Vertebrate Animals ,Estrogenic Compounds ,Pesticide ,Biology ,Environmental Estrogen ,chemistry.chemical_compound ,Food chain ,chemistry ,Biochemistry ,Insect Science ,Xenobiotic - Abstract
Over the past three decades, a substantial body of evidence has accumulated on the estrogenic activities of numerous environmental compounds. These “environmental estrogens,” consisting of pesticides and a variety of industrial chemicals and their by-products, are becoming ubiquitous in the environment and are making their way into the food chain. An important issue is whether vertebrate animals are equipped with mechanisms for the inactivation and/or disposal of environmental estrogens. This review attempts to summarize the currently available data concerning the sulfation of environmental estrogenic compounds by the cytosolic sulfotransferases in vertebrate animals. © Pesticide Science Society of Japan
- Published
- 2005
29. pH-profile crystal structure studies of C-terminal despentapeptide nitrite reductase from Achromobacter cycloclastes
- Author
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Xiao Min An, Jean Le Gall, Lu Lu Gui, Wen Chang Chang, Jiping Zhang, Tschining Chang, Wenrui Chang, Haitao Li, Chao Wang, and Ming Yih Liu
- Subjects
Models, Molecular ,Nitrite Reductases ,Stereochemistry ,Biophysics ,chemistry.chemical_element ,Crystal structure ,Crystallography, X-Ray ,Achromobacter cycloclastes ,Biochemistry ,Active center ,Bacterial Proteins ,Oxidoreductase ,Catalytic Domain ,Molecular Biology ,Sequence Deletion ,chemistry.chemical_classification ,biology ,Hydrogen bond ,Cell Biology ,Hydrogen-Ion Concentration ,Nitrite reductase ,Copper ,Enzyme assay ,Enzyme ,chemistry ,biology.protein - Abstract
Crystal structures of C-terminal despentapeptide nitrite reductase (NiRc-5) from Achromobacter cycloclastes were determined from 1.9 to 2.3 A at pH 5.0, 5.4, and 6.2. NiRc-5, that has lost about 30% activity, is found to possess quite similar trimeric structures as the native enzyme. Electron density and copper content measurements indicate that the activity loss is not caused by the release of type 2 copper (T2Cu). pH-profile structural comparisons with native enzyme reveal that the T2Cu active center in NiRc-5 is perturbed, accounting for the partial loss of enzyme activity. This perturbation likely results from the less constrained conformations of two catalytic residues, Asp98 and His255. Hydrogen bonding analysis shows that the deletion of five residues causes a loss of more than half the intersubunit hydrogen bonds mediated by C-terminal tail. This study shows that the C-terminal tail plays an important role in controlling the conformations around the T2Cu site at the subunit interface, and helps keep the optimum microenvironment of active center for the full enzyme activity of AcNiR.
- Published
- 2004
30. Sulfonation of environmental estrogens by zebrafish cytosolic sulfotransferases
- Author
-
Takuya Sugahara, Yoichi Sakakibara, Masahito Suiko, Glendora Carter, Ming-Cheh Liu, Kei Ohkimoto, and Ming-Yih Liu
- Subjects
endocrine system ,medicine.medical_specialty ,Bisphenol A ,DNA, Complementary ,Biophysics ,Diethylstilbestrol ,Endogeny ,Environment ,Ethinyl Estradiol ,Biochemistry ,chemistry.chemical_compound ,Cytosol ,Estradiol Congeners ,Phenols ,Internal medicine ,medicine ,Animals ,Protein Isoforms ,Estrogens, Non-Steroidal ,Benzhydryl Compounds ,Molecular Biology ,Zebrafish ,chemistry.chemical_classification ,Dose-Response Relationship, Drug ,biology ,Chemistry ,Estrogens ,Cell Biology ,Metabolism ,biology.organism_classification ,Recombinant Proteins ,Kinetics ,Enzyme ,Endocrinology ,Electrophoresis, Polyacrylamide Gel ,Sulfotransferases ,hormones, hormone substitutes, and hormone antagonists ,Plasmids ,medicine.drug - Abstract
Environmental estrogen-like chemicals are increasingly recognized as a potential hazardous factor for wildlife as well as humans. We have recently embarked on developing a zebrafish model for investigating the role of sulfonation in the metabolism and adverse functioning of environmental estrogens. Here, we report on a systematic investigation of the sulfonation of representative environmental estrogens (bisphenol A, 4-n-octylphenol, 4-n-nolylphenol, diethylstilbestrol, and 17 alpha-ethynylestradiol) by zebrafish cytosolic sulfotransferases (STs). Of the seven enzymes tested, four zebrafish STs (designated ZF ST #2, ZF ST #3, ZF ST #4, and ZF DHEA ST) exhibited differential sulfonating activities toward the five environmental estrogens tested, with ZF ST #3 being more highly active than the other three. It was further demonstrated that bisphenol A, 4-n-octylphenol, and 4-n-nonylphenol exerted concentration-dependent inhibition of the sulfonation of 17 beta-estradiol, implying a potential role of these environmental estrogens in interfering with the sulfonation, and possibly homeostasis, of endogenous estrogens. Kinetic studies revealed that the mechanism underlying the inhibition by bisphenol A or 4-n-nonylphenol to be of the competitive type.
- Published
- 2003
31. Preparation and X-ray crystallographic analysis of rubredoxin crystals from Desulfovibrio gigas to beyond ultra-high 0.68 Å resolution
- Author
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Yi-Ting Chen, Ming-Yih Liu, Jean LeGall, and Chun-Jung Chen
- Subjects
Iron ,Biophysics ,Ab initio ,Electrons ,Crystal structure ,Crystallography, X-Ray ,Biochemistry ,law.invention ,Crystal ,law ,Rubredoxin ,Desulfovibrio gigas ,Crystallization ,Molecular Biology ,biology ,Chemistry ,Rubredoxins ,X-Rays ,Resolution (electron density) ,Cell Biology ,biology.organism_classification ,Desulfovibrio ,Crystallography ,Models, Chemical ,Mutation ,Oxidation-Reduction ,Sulfur - Abstract
Rubredoxin (D.g. Rd), a small non-heme iron-sulfur protein shown to function as a redox coupling protein from the sulfate reducing bacteria Desulfovibrio gigas, has been crystallized using the hanging-drop vapor diffusion method and macroseeding method. Rubredoxin crystals diffract to an ultra-high resolution 0.68 A using synchrotron radiation X-ray, and belong to the space group P2(1) with unit-cell parameters a=19.44 A, b=41.24 A, c=24.10 A, and beta=108.46 degrees. The data set of single-wavelength anomalous dispersion signal of iron in the native crystal was also collected for ab initio structure re-determination. Preliminary analysis indicates that there is one monomer with a [Fe-4S] cluster in each asymmetric unit. The crystal structure at this ultra-high resolution will reveal the details of its biological function. The crystal character and data collection strategy for ultra-high resolution will also be discussed.
- Published
- 2003
32. Crystal structure studies on rubrerythrin: enzymatic activity in relation to the zinc movement
- Author
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Jun Liao, Wenrui Chang, Dong-Cai Liang, Jiping Zhang, Mei Li, Tao Jiang, Ming-Yih Liu, Lulu Gui, and Jean LeGall
- Subjects
Models, Molecular ,Iron ,chemistry.chemical_element ,Rubrerythrin ,Zinc ,Crystal structure ,Crystallography, X-Ray ,Biochemistry ,Inorganic Chemistry ,Crystal ,Metal ,chemistry.chemical_compound ,Bacterial Proteins ,Molecule ,Desulfovibrio vulgaris ,Pyrophosphatases ,biology ,Rubredoxins ,biology.organism_classification ,Hemerythrin ,Crystallography ,Monomer ,chemistry ,visual_art ,visual_art.visual_art_medium ,Ferredoxins ,Dimerization ,Oxidation-Reduction - Abstract
Rubrerythrin (Rr) is a non-heme iron protein isolated from anaerobic sulfate-reducing bacteria. Rr is a dimeric molecule, each monomer contains a Fe(SCys)4 center in the C-terminal domain and a binuclear metal center in the N-terminal domain. Rr structures with different protein sources and/or preparation procedures have been studied. Two Rr crystal structures have been solved with significant differences in their binuclear metal centers. The first structure, which was obtained from expressed protein under aerobic conditions, has a diiron–oxo center. The second structure, which was obtained from native protein of Desulfovibrio vulgaris under aerobic conditions, has an Fe–Zn center with the zinc position differing from the corresponding iron position in the former structure by approximately 2 A. The crystal structures of Rr isolated from D. vulgaris (Hildenborough, NCIB 8303), the same as the second structured but prepared under anaerobic conditions, are reported in this paper. The binuclear metal center in these structures is an Fe–Zn center. When the crystal was exposed to air, the zinc atom moved gradually, approximately 2 A, accompanied by the entrance of a water molecule (or hydroxyl group) and changes in the binuclear metal center microenvironment. This finding can explain the differences between the two different structures. The results suggest that the zinc movement may be related to the enzymatic activity of Rr. Electronic supplementary material is available if you access this article at http://dx.doi.org/10.1007/s00775-002-0400-0. On that page (frame on the left side), a link takes you directly to the supplementary material.
- Published
- 2003
33. Preliminary crystallographic studies of two C-terminally truncated copper-containing nitrite reductases from Achromobacter cycloclastes: changed crystallizing behaviors caused by residue deletion
- Author
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Ming Yih Liu, Dong Cai Liang, Xiao Min An, Wenrui Chang, Jiping Zhang, Haitao Li, Tschining Chang, Lu Lu Gui, and Jean Le Gall
- Subjects
Models, Molecular ,Nitrite Reductases ,Stereochemistry ,Mutant ,Biophysics ,chemistry.chemical_element ,Crystallography, X-Ray ,Biochemistry ,Residue (chemistry) ,Alcaligenes ,Molecular Biology ,Sequence Deletion ,chemistry.chemical_classification ,biology ,Cell Biology ,Nitrite reductase ,Copper ,Enzyme assay ,Crystallography ,Enzyme ,chemistry ,biology.protein ,Protein quaternary structure ,Crystallization ,Monoclinic crystal system - Abstract
The C-terminal segment of copper-containing nitrite reductase from Achromobacter cycloclastes (AcNiR) has been found essential for maintaining both the quaternary structure and the enzyme activity of AcNiR. C-terminal despentapeptide AcNiR (NiRc-5) and desundecapeptide AcNiR (NiRc-11) are two important truncated mutants whose activities and stability have been affected by residue deletion. In this study, the two mutants were crystallized using the hanging drop vapor diffusion method. Crystals of NiRc-5 obtained at pH 5.0 and 6.2 both belonged to the P2(1)2(1)2(1) space group with unit cell parameters a=99.0 A, b=117.4 A, c=122.8 A (pH 5.0) and a=98.9A, b=117.7A, c=123.0A (pH 6.2). NiRc-11 was crystallized in two crystal forms: the tetragonal form belonged to the space group P4(1) with a=b=96.0A and c=146.6A; the monoclinic form belonged to the space group P2(1) with a=86.0A, b=110.1A, c=122.7A, and beta=101.9 degrees. The crystallizing behaviors of the two mutants differed from that of the native enzyme. Such change in combination with residue deletion is also discussed here.
- Published
- 2002
34. Three-dimensional structure of manganese superoxide dismutase from Bacillus halodenitrificans, a component of the so-called 'green protein'
- Author
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Tschining Chang, Jiping Zhang, Jean Le Gall, Jun Liao, Mei Li, Tao Jiang, Ming Yih Liu, Dong Cai Liang, Wenrui Chang, and Lu Lu Gui
- Subjects
Models, Molecular ,Denitrification ,animal diseases ,Molecular Sequence Data ,Static Electricity ,chemistry.chemical_element ,Bacillus ,Manganese ,Crystallography, X-Ray ,Catalysis ,Structure-Activity Relationship ,Bacterial Proteins ,Structural Biology ,Oxidoreductase ,Amino Acid Sequence ,Protein Structure, Quaternary ,chemistry.chemical_classification ,Binding Sites ,Sequence Homology, Amino Acid ,Superoxide Dismutase ,Chemistry ,fungi ,Substrate (chemistry) ,Nucleoside-diphosphate kinase ,Halophile ,Zinc ,Biochemistry ,Cytoplasm ,Salts - Abstract
A so-called "green protein" has been purified from a moderate halophilic eubacterium, Bacillus halodenitrificans (ATCC 49067), under anaerobic conditions. The protein, which might play an important role in denitrification, dissociates mainly into two components after exposure to air: a manganese superoxide dismutase (GP-MnSOD) and a nucleoside diphosphate kinase. As a first step in elucidating the overall structure of the green protein and the role of each component, the 2.8-A resolution crystal structure of GP-MnSOD was determined. Compared with other manganese dismutases, GP-MnSOD shows two significant characteristics. The first is that the entrance to its substrate channel has an additional basic residue-Lys38. The second is that its surface is decorated with an excess of acidic over basic residues. All these structural features may be related to GP-MnSOD's high catalytic activity and its endurance against the special cytoplasm of B. halodenitrificans. The structure of GP-MnSOD provides the basis for recognizing its possible role and assembly state in the green protein.
- Published
- 2002
35. Sulfation of phenylephrine by the human cytosolic sulfotransferases
- Author
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Ming-Cheh Liu, Masahito Suiko, Yoichi Sakakibara, Jiwan Kim, Katsuhisa Kurogi, Akihiro Yamamoto, and Ming-Yih Liu
- Subjects
medicine.medical_specialty ,Clinical Biochemistry ,Pharmaceutical Science ,Phenylephrine ,Sulfation ,Cytosol ,Dopamine ,In vivo ,Internal medicine ,medicine ,Humans ,Pharmacology (medical) ,chemistry.chemical_classification ,Chemistry ,Sulfates ,Biochemistry (medical) ,Metabolism ,Hep G2 Cells ,Hydrogen-Ion Concentration ,Arylsulfotransferase ,Kinetics ,Endocrinology ,Enzyme ,Hepg2 cells ,Adrenergic alpha-1 Receptor Agonists ,Sulfotransferases ,medicine.drug - Abstract
Previous studies had demonstrated that sulfation constituted a major pathway for the metabolism of phenylephrine in vivo. The current study was designed to identify the major human SULT(s) responsible for the sulfation of phenylephrine. Of the twelve human SULTs analyzed, SULT1A3 displayed the strongest sulfating activity toward phenylephrine. The enzyme exhibited a pH optimum spanning 7 – 10.5. Kinetic analysis revealed that SULT1A3- mediated sulfation of phenylephrine occurred in the same order of magnitude compared with that previously reported for SULT1A3-mediated sulfation of dopamine. Moreover, sulfation of phenylephrine was shown to occur in HepG2 cells under metabolic setting. Collectively, these results provided useful information concerning the biochemical basis underlying the metabolism of phenylephrine in vivo as previously reported.
- Published
- 2014
36. Iron-coproporphyrin III is a natural cofactor in bacterioferritin from the anaerobic bacteriumDesulfovibrio desulfuricans
- Author
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Ricardo O. Louro, Ming-Yih Liu, Célia V. Romão, Mathias Lübben, António V. Xavier, Russel Timkovich, Miguel Teixeira, and Jean LeGall
- Subjects
Coproporphyrins ,Bacterioferritin ,Heme biosynthesis ,Biophysics ,Anaerobic bacterium ,Heme ,Biochemistry ,Cofactor ,Coproporphyrin ,Bacterial Proteins ,Structural Biology ,polycyclic compounds ,Genetics ,Anaerobiosis ,Nuclear Magnetic Resonance, Biomolecular ,Molecular Biology ,Molecular Structure ,biology ,digestive, oral, and skin physiology ,Cell Biology ,Iron coproporphyrin ,Desulfovibrio desulfuricans ,Cytochrome b Group ,biology.organism_classification ,Unexpected finding ,Ferritins ,biology.protein ,Desulfovibrio ,Bacteria - Abstract
A bacterioferritin was recently isolated from the anaerobic sulphate-reducing bacterium Desulfovibrio desulfuricans ATCC 27774 [Romão et al. (2000) Biochemistry 39, 6841–6849]. Although its properties are in general similar to those of the other bacterioferritins, it contains a haem quite distinct from the haem B, found in bacterioferritins from aerobic organisms. Using visible and NMR spectroscopies, as well as mass spectrometry analysis, the haem is now unambiguously identified as iron-coproporphyrin III, the first example of such a prosthetic group in a biological system. This unexpected finding is discussed in the framework of haem biosynthetic pathways in anaerobes and particularly in sulphate-reducing bacteria.
- Published
- 2000
37. Molecular Cloning of the Gene Encoding Flavoredoxin, a Flavoprotein from Desulfovibrio gigas
- Author
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Jean LeGall, Claudina Rodrigues-Pousada, Ming-Yih Liu, Marta Agostinho, Manuela Broco, and Solange Oliveira
- Subjects
FMN Reductase ,Flavin Mononucleotide ,Molecular Sequence Data ,Biophysics ,Flavoprotein ,Flavin group ,Biology ,Molecular cloning ,Biochemistry ,Open Reading Frames ,FMN binding ,Bacterial Proteins ,Sulfites ,Desulfovibrio gigas ,NADH, NADPH Oxidoreductases ,Amino Acid Sequence ,Cloning, Molecular ,Molecular Biology ,Peptide sequence ,Binding Sites ,Base Sequence ,Flavoproteins ,Sequence Homology, Amino Acid ,Cell Biology ,Molecular Weight ,Bisulfite ,biology.protein ,Desulfovibrio ,Oxidoreductases ,Energy source ,Hydrogen - Abstract
Sulfate-reducing bacteria are rich in unique redox proteins and electron carriers that participate in a variety of essential pathways. Several studies have been carried out to characterize these proteins, but the structure and function of many are poorly understood. Many Desulfovibrio species can grow using hydrogen as the sole energy source, indicating that the oxidation of hydrogen with sulfite as the terminal electron acceptor is an energy-conserving mechanism. Flavoredoxin is an FMN-binding protein isolated from the sulfate-reducing bacteria Desulfovibrio gigas that participates in the reduction of bisulfite from hydrogen. Here we report the cloning and sequencing of the flavoredoxin gene. The derived amino acid sequence exhibits similarity to several flavoproteins which are members of a new family of flavin reductases suggested to bind FMN in a novel mode.
- Published
- 2000
38. Purification and Characterization of an Iron Superoxide Dismutase and a Catalase from the Sulfate-Reducing Bacterium Desulfovibrio gigas
- Author
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António V. Xavier, Miguel Teixeira, Wagner G. Dos Santos, Jean LeGall, Isabel Pacheco, and Ming-Yih Liu
- Subjects
Cyanide ,Molecular Sequence Data ,Microbiology ,Superoxide dismutase ,Magnetics ,chemistry.chemical_compound ,Desulfovibrio gigas ,Amino Acid Sequence ,Anaerobiosis ,Amino Acids ,Molecular Biology ,Heme ,chemistry.chemical_classification ,biology ,Superoxide Dismutase ,Catalase ,biology.organism_classification ,Enzymes and Proteins ,Desulfovibrio ,Enzyme ,chemistry ,Biochemistry ,biology.protein ,Electrophoresis, Polyacrylamide Gel ,Peroxidase - Abstract
The iron-containing superoxide dismutase (FeSOD; EC 1.15.1.1 ) and catalase (EC 1.11.1.6 ) enzymes constitutively expressed by the strictly anaerobic bacterium Desulfovibrio gigas were purified and characterized. The FeSOD, isolated as a homodimer of 22-kDa subunits, has a specific activity of 1,900 U/mg and exhibits an electron paramagnetic resonance (EPR) spectrum characteristic of high-spin ferric iron in a rhombically distorted ligand field. Like other FeSODs from different organisms, D. gigas FeSOD is sensitive to H 2 O 2 and azide but not to cyanide. The N-terminal amino acid sequence shows a high degree of homology with other SODs from different sources. On the other hand, D. gigas catalase has an estimated molecular mass of 186 ± 8 kDa, consisting of three subunits of 61 kDa, and shows no peroxidase activity. This enzyme is very sensitive to H 2 O 2 and cyanide and only slightly sensitive to sulfide. The native enzyme contains one heme per molecule and exhibits a characteristic high-spin ferric-heme EPR spectrum ( g y , x = 6.4, 5.4); it has a specific activity of 4,200 U/mg, which is unusually low for this class of enzyme. The importance of these two enzymes in the context of oxygen utilization by this anaerobic organism is discussed.
- Published
- 2000
39. Purification, crystallization and preliminary X-ray crystallographic analysis of xylose reductase fromCandida tropicalis
- Author
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Li Chun Chen, Yu Ching Chen, Chung Der Chen, Sheng Cih Huang, Yen-Chieh Huang, Ming Yih Liu, Tung-Kung Wu, Hsiao Fang Pang, Jeyaraman Jeyakanthan, Chun-Jung Chen, Phimonphan Chuankhayan, Yu Kuo Wang, and Lee Chung Men
- Subjects
Biophysics ,Xylose ,Crystallography, X-Ray ,Xylitol ,Biochemistry ,law.invention ,Candida tropicalis ,chemistry.chemical_compound ,Aldehyde Reductase ,Structural Biology ,law ,Genetics ,Crystallization ,Molecular mass ,biology ,food and beverages ,Space group ,Condensed Matter Physics ,biology.organism_classification ,Solvent ,Crystallography ,chemistry ,Crystallization Communications ,Electrophoresis, Polyacrylamide Gel - Abstract
Xylose reductase (XR), which requires NADPH as a co-substrate, catalyzes the reduction of D-xylose to xylitol, which is the first step in the metabolism of D-xylose. The detailed three-dimensional structure of XR will provide a better understanding of the biological significance of XR in the efficient production of xylitol from biomass. XR of molecular mass 36.6 kDa from Candida tropicalis was crystallized using the hanging-drop vapour-diffusion method. According to X-ray diffraction data from C. tropicalis XR crystals at 2.91 A resolution, the unit cell belongs to space group P3(1) or P3(2). Preliminary analysis indicated the presence of four XR molecules in the asymmetric unit, with 68.0% solvent content.
- Published
- 2009
40. Purification, crystallization and preliminary X-ray crystallographic analysis of branched-chain aminotransferase fromDeinococcus radiodurans
- Author
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Yin Cheng Hsieh, Yen-Chieh Huang, Ming Yih Liu, Hong Hsiang Guan, Yi Hung Lin, Tien Feng Huang, Chih Hao Lin, Chung Der Chen, Wen Chang Chang, and Chun-Jung Chen
- Subjects
Branched chain aminotransferase ,Biophysics ,Crystallography, X-Ray ,Biochemistry ,chemistry.chemical_compound ,Bacterial Proteins ,Leucine ,Structural Biology ,Valine ,Genetics ,Deinococcus ,Isoleucine ,Pyridoxal ,Transaminases ,chemistry.chemical_classification ,biology ,Deinococcus radiodurans ,Condensed Matter Physics ,biology.organism_classification ,Amino acid ,Crystallography ,chemistry ,Crystallization Communications ,Crystallization - Abstract
The branched-chain amino-acid aminotransferase (BCAT), which requires pyridoxal 5'-phosphate (PLP) as a cofactor, is a key enzyme in the biosynthetic pathway of the hydrophobic amino acids leucine, isoleucine and valine. DrBCAT from Deinococcus radiodurans, which has a molecular weight of 40.9 kDa, was crystallized using the hanging-drop vapour-diffusion method. According to X-ray diffraction data to 2.50 A resolution from a DrBCAT crystal, the crystal belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 56.37, b = 90.70, c = 155.47 A. Preliminary analysis indicates the presence of two DrBCAT molecules in the asymmetric unit, with a solvent content of 47.52%.
- Published
- 2007
41. The C-Terminal Segment Is Essential for Maintaining the Quaternary Structure and Enzyme Activity of the Nitric Oxide Forming Nitrite Reductase fromAchromobacter cycloclastes
- Author
-
William J. Payne, Tschining Chang, Jang-Yi Chen, Ming Yih Liu, Wen Chang Chang, Wei Chao Chang, and Jean LeGall
- Subjects
Nitrite Reductases ,Protein Conformation ,Stereochemistry ,Biophysics ,Trimer ,Crystallography, X-Ray ,Nitric Oxide ,Biochemistry ,Pentapeptide repeat ,Structure-Activity Relationship ,Enzyme activator ,Protein structure ,Structure–activity relationship ,Alcaligenes ,neoplasms ,Molecular Biology ,biology ,Chemistry ,technology, industry, and agriculture ,Cell Biology ,equipment and supplies ,Nitrite reductase ,Enzyme assay ,Enzyme Activation ,surgical procedures, operative ,biology.protein ,Protein quaternary structure - Abstract
We have constructed and expressed a series of mutated nitrite reductase (NIR) mutants based on the sequence of NIR from Achromobacter cycloclastes. Deleting a pentapeptide, an undecapeptide, or a heptadecapeptide from the C-terminus of NIR resulted in a series of C-terminal deletion mutated proteins designated as NIR-5, NIR-11, and NIR-17, respectively. A C-terminally extended mutated protein, NIR+8, was also produced, which contains an extra octapeptide attached to the C-terminus of the wild-type NIR. An SDS-PAGE system using tris-tricine buffer could retain the native NIR in its trimeric form, thus offering a convenient method to check the quaternary structure of NIR analogs. By using this system it was found that NIR-5 was maintained as trimer and retained 72% of wild-type enzyme activity. However, both NIR-11 and NIR-17 behaved as monomers in the SDS-PAGE and lost all their enzyme activity. Although NIR+8 maintained its trimeric structure it was enzymatically inactive. These results clearly indicate that the C-terminal undecapeptide is essential for maintaining the quaternary structure as well as the full enzymatic activity, as expected from the X-ray crystallography studies.
- Published
- 1998
42. Cloning, Characterization, and Expression of the Nitric Oxide-Generating Nitrite Reductase and of the Blue Copper Protein Genes ofAchromobacter cycloclastes
- Author
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Jean LeGall, Ming Yih Liu, Tschining Chang, William J. Payne, Wei Chao Chang, Wen Chang Chang, and Jang-Yi Chen
- Subjects
Signal peptide ,Nitrite Reductases ,Copper protein ,Molecular Sequence Data ,Biophysics ,Gene Expression ,Biology ,Nitric Oxide ,Biochemistry ,chemistry.chemical_compound ,Bacterial Proteins ,Metalloproteins ,Coding region ,Alcaligenes ,Amino Acid Sequence ,Cloning, Molecular ,Molecular Biology ,Gene ,Peptide sequence ,DNA Primers ,Genomic Library ,Base Sequence ,Edman degradation ,Cell Biology ,Nitrite reductase ,Molecular biology ,Recombinant Proteins ,Molecular Weight ,chemistry ,Genes, Bacterial ,DNA - Abstract
The nitrite reductase (NIR) and blue copper protein (BCP) genes have been cloned from Achromobacter cycloclastes and characterized. NIR gene encodes a protein of 378 amino acid residues including a putative signal peptide of 37 residues. BCP gene encodes a protein of 148 residues with a 24-residue signal peptide. The DNA-derived amino acid sequence of NIR is in complete agreement with that from Edman degradation and the DNA coding sequence of BCP is also consistent with its partial N-terminal amino acid sequence. Both genes contain their own FNR box in the 5' upstream region and a TA-rich region that could be the transcription start site. These two genes are separated by at least 10 kb. Based on these observations it is very likely that these two genes, although functionally related, are regulated independently. Both proteins could be expressed in E. coli, and both of the expressed proteins could be recognized by their respective antisera. The expressed NIR demonstrates full enzymatic activity. The similarity of both proteins to the counterparts from Alcaligenes faecalis S-6 is discussed.
- Published
- 1996
43. Siroamide: A Prosthetic Group Isolated from Sulfite Reductases in the Genus Desulfovibrio
- Author
-
J. Le Gall, Ming-Yih Liu, R. Timkovich, and J. C. Matthews
- Subjects
chemistry.chemical_classification ,Magnetic Resonance Spectroscopy ,biology ,Stereochemistry ,Heme ,Nuclear magnetic resonance spectroscopy ,biology.organism_classification ,Biochemistry ,Desulfovibrio ,Cofactor ,Microbiology ,chemistry.chemical_compound ,Enzyme ,Sulfite ,chemistry ,Siroheme ,Amide ,biology.protein ,Oxidoreductases Acting on Sulfur Group Donors ,Derivative (chemistry) - Abstract
While isolating siroheme from enzymes or whole cells of Desulfovibrio species, it was discovered that the main product after metal removal and esterification was not the octamethyl ester derivative of sirohydrochlorin, but a monoamide, heptamethyl ester derivative. The structure of this derivative was established by mass spectrometry and NMR. Nuclear Overhauser enhancement measurements in combination with chemical shift analogy arguments indicate that the 2(1)-acetate has been stereospecifically amidated. Other cellular sources of siroheme were investigated, but only the octamethyl ester derivative was found, with no traces of the amide derivative. The results suggest that, in Desulfovibrio, the physiologically active prosthetic group may be an amidated form of siroheme.
- Published
- 1995
44. Crystal structures of complexes of the branched-chain aminotransferase from Deinococcus radiodurans with α-ketoisocaproate and L-glutamate suggest the radiation resistance of this enzyme for catalysis
- Author
-
Yen-Chieh Huang, Tien-Feng Huang, Chung-De Chen, Hong-Hsiang Guan, Chih Hao Lin, Wen Chang Chang, Chun-Jung Chen, Phimonphan Chuankhayan, Yin-Cheng Hsieh, and Ming-Yih Liu
- Subjects
Models, Molecular ,Stereochemistry ,Protein Conformation ,Branched chain aminotransferase ,Molecular Sequence Data ,Glutamic Acid ,Crystallography, X-Ray ,Microbiology ,Catalysis ,Gene Expression Regulation, Enzymologic ,Substrate Specificity ,Catalytic Domain ,Enzyme Stability ,Amino Acid Sequence ,Molecular Biology ,Transaminases ,chemistry.chemical_classification ,biology ,Active site ,Deinococcus radiodurans ,Gene Expression Regulation, Bacterial ,Articles ,Thermus thermophilus ,biology.organism_classification ,Keto Acids ,Amino acid ,Biochemistry ,chemistry ,Spectrophotometry ,biology.protein ,Salt bridge ,Deinococcus ,Leucine ,Isoleucine ,Crystallization - Abstract
Branched-chain aminotransferases (BCAT), which utilize pyridoxal 5′-phosphate (PLP) as a cofactor, reversibly catalyze the transfer of the α-amino groups of three of the most hydrophobic branched-chain amino acids (BCAA), leucine, isoleucine, and valine, to α-ketoglutarate to form the respective branched-chain α-keto acids and glutamate. The BCAT from Deinococcus radiodurans ( Dr BCAT), an extremophile, was cloned and expressed in Escherichia coli for structure and functional studies. The crystal structures of the native Dr BCAT with PLP and its complexes with l -glutamate and α-ketoisocaproate (KIC), respectively, have been determined. The Dr BCAT monomer, comprising 358 amino acids, contains large and small domains connected with an interdomain loop. The cofactor PLP is located at the bottom of the active site pocket between two domains and near the dimer interface. The substrate ( l -glutamate or KIC) is bound with key residues through interactions of the hydrogen bond and the salt bridge near PLP inside the active site pocket. Mutations of some interaction residues, such as Tyr71, Arg145, and Lys202, result in loss of the specific activity of the enzymes. In the interdomain loop, a dynamic loop (Gly173 to Gly179) clearly exhibits open and close conformations in structures of Dr BCAT without and with substrates, respectively. Dr BCAT shows the highest specific activity both in nature and under ionizing radiation, but with lower thermal stability above 60°C, than either BCAT from Escherichia coli ( e BCAT) or from Thermus thermophilus (HB8BCAT). The dimeric molecular packing and the distribution of cysteine residues at the active site and the molecular surface might explain the resistance to radiation but small thermal stability of Dr BCAT.
- Published
- 2012
45. Concerted actions of the catechol O-methyltransferase and the cytosolic sulfotransferase SULT1A3 in the metabolism of catecholic drugs
- Author
-
Takuya Sugahara, Masahito Suiko, Adnan Alazizi, Ming-Yih Liu, Ming-Cheh Liu, Yoichi Sakakibara, and Katsuhisa Kurogi
- Subjects
Sulfotransferase ,Metabolite ,Catechols ,Sulfuric Acid Esters ,Catechol O-Methyltransferase ,Biochemistry ,Methylation ,Article ,Tropolone ,chemistry.chemical_compound ,Sulfation ,Dopamine ,medicine ,Humans ,Pharmacology ,Catechol-O-methyl transferase ,Isoetharine ,Catechol O-Methyltransferase Inhibitors ,Hep G2 Cells ,Arylsulfotransferase ,chemistry ,Solubility ,Sulfotransferases ,medicine.drug - Abstract
Catecholic drugs had been reported to be metabolized through conjugation reactions, particularly methylation and sulfation. Whether and how these two Phase II conjugation reactions may occur in a concerted manner, however, remained unclear. The current study was designed to investigate the methylation and/or sulfation of five catecholic drugs. Analysis of the spent media of HepG2 cells metabolically labeled with [(35)S]sulfate in the presence of individual catecholic drugs revealed the presence of two [(35)S]sulfated metabolites for dopamine, epinephrine, isoproterenol, and isoetharine, but only one [(35)S]sulfated metabolite for apomorphine. Further analyses using tropolone, a catechol O-methyltransferase (COMT) inhibitor, indicated that one of the two [(35)S]sulfated metabolites of dopamine, epinephrine, isoproterenol, and isoetharine was a doubly conjugated (methylated and sulfated) product, since its level decreased proportionately with increasing concentrations of tropolone added to the labeling media. Moreover, while the inhibition of methylation resulted in a decrease of the total amount of [(35)S]sulfated metabolites, sulfation appeared to be capable of compensating the suppressed methylation in the metabolism of these four catecholic drugs. A two-stage enzymatic assay showed the sequential methylation and sulfation of dopamine, epinephrine, isoproterenol, and isoetharine mediated by, respectively, the COMT and the cytosolic sulfotransferase SULT1A3. Collectively, the results from the present study implied the concerted actions of the COMT and SULT1A3 in the metabolism of catecholic drugs.
- Published
- 2012
46. An unusual hemoprotein capable of reversible binding of nitric oxide from the gram-positive Bacillus halodenitrificans
- Author
-
Ming Yih Liu, Paul A. Ketchum, Gerard Denariaz, Isabel Moura, Jean LeGall, William J. Payne, and José J. G. Moura
- Subjects
Hemeprotein ,Cytochrome ,biology ,Inorganic chemistry ,General Medicine ,Photochemistry ,Dithionite ,Biochemistry ,Microbiology ,Cofactor ,Nitric oxide ,chemistry.chemical_compound ,chemistry ,Chromoprotein ,Genetics ,biology.protein ,medicine ,Ferric ,Molecular Biology ,Heme ,medicine.drug - Abstract
A green protein from the soluble extract of anaerobically grown Bacillus halodenitrificans cells was purified and determined by non-denaturing procedures or SDS-PAGE to have a molecular mass of 64 kDa. The pyridine hemochromogen was shown to be that of a b-type cytochrome prosthetic group that was soluble in ether. The protein contained 6.2mol protoheme per mol protein-1. Photoreduction of the native protein yielded a product with an electronic absorption spectrum retaining the 559 nm maximum and the 424-nm Soret band displayed in the dithionite-reduced sample. Incubation of a reduced sample in the presence of air failed to return it to the original oxidation state. Electronic spin was not affected by pH. The reduced but not the oxidized form of the cytochrome bound cyanide, carbon monoxide, and nitric oxide, providing spectra resembling those of cytochromes c′ from several sources. Addition of nitroprusside to the reduced protein yielded a spectrum similar to that of the NO reacted protein. Nitric oxide failed to reduce the green protein. The position of the Soret band in the spectrum of the nitric oxide derivative of the green protein suggested a fifth-coordinate nitrosylheme structure. EPR studies provided g values with the triplet spectral pattern consistent with a five-coordinate ferrous nitrosyl heme. Flushing of the NO-derivative with argon and overnight exposure to air returned the nitrosylheme to the ferric form, and EPR values confirmed the reversion. All these spectral characterizations are strikingly similar to those of soluble guanylate cyclase, including the observation that NO was reversibly bound to the protein. EPR spectra of whole cells also displayed the hyperfine lines typical of a nitrosyl-ferrous heme, accentuated when dithionite was added. In the absence of a definitive physiological role because of its unusual properties, the green protein was named a nitric oxide-binding protein.
- Published
- 1994
47. Crystallization and preliminary crystallographic analysis of manganese superoxide dismutase from Bacillus halodenitrificans
- Author
-
Tschining Chang, Ming-Yih Liu, Dong-Cai Liang, Jiping Zhang, Mei Li, Jun Liao, Jean Le Gall, Wenrui Chang, and Lulu Gui
- Subjects
chemistry.chemical_classification ,biology ,Protein Conformation ,Superoxide Dismutase ,Biophysics ,Bacillus ,Cell Biology ,Crystallography, X-Ray ,Biochemistry ,Manganese Superoxide Dismutase ,Halophile ,Catalysis ,law.invention ,Superoxide dismutase ,Crystallography ,chemistry.chemical_compound ,Enzyme ,Monomer ,chemistry ,law ,biology.protein ,Crystallization ,Molecular Biology ,Bacillus halodenitrificans - Abstract
Manganese superoxide dismutase (GP-MnSOD), a component of the so-called `green protein' (green protein complex) from the facultative anaerobic halodenitrifier Bacillus halodenitrificans , has been crystallized using the hanging-drop vapor diffusion method. Crystals have unit-cell parameters a = b =93.4 A, c =65.0 A, and belong to the space group P4 3 2 1 2. Preliminary analysis indicates there is one monomer in each asymmetric unit. The structural information from this enzyme will enrich our knowledge on its high catalytic activity and its possible role in green protein complex.
- Published
- 2002
48. Identification and characterization of zebrafish SULT1 ST9, SULT3 ST4, and SULT3 ST5
- Author
-
Masahito Suiko, Katsuhisa Kurogi, Ming-Yih Liu, Shakhawat Bhuiyan, Yoichi Sakakibara, Zheng Xu, Ming-Cheh Liu, Frederick E. Williams, Yasir Ihsan Mohammed, and Amani Al Shaban
- Subjects
Health, Toxicology and Mutagenesis ,Molecular Sequence Data ,Dehydroepiandrosterone ,Aquatic Science ,Article ,Substrate Specificity ,chemistry.chemical_compound ,Cytosol ,Caffeic acid ,medicine ,Animals ,Cluster Analysis ,Gallic acid ,Amino Acid Sequence ,Zebrafish ,chemistry.chemical_classification ,biology ,Gene Expression Regulation, Developmental ,Metabolism ,Hydrogen-Ion Concentration ,Zebrafish Proteins ,biology.organism_classification ,Molecular biology ,Recombinant Proteins ,Kinetics ,Enzyme ,Biochemistry ,chemistry ,Pregnenolone ,Sulfotransferases ,Xenobiotic ,Sequence Alignment ,medicine.drug ,Protein Binding - Abstract
By searching the GenBank database, we identified sequences encoding three new zebrafish cytosolic sulfotransferases (SULTs). These three new zebrafish SULTs, designated SULT1 ST9, SULT3 ST4, and SULT3 ST5, were cloned, expressed, purified, and characterized. SULT1 ST9 appeared to be mostly involved in the metabolism and detoxification of xenobiotics such as β-naphthol, β-naphthylamine, caffeic acid and gallic acid. SULT3 ST4 showed strong activity toward endogenous compounds such as dehydroepiandrosterone (DHEA), pregnenolone, and 17β-estradiol. SULT3 ST5 showed weaker, but significant, activities toward endogenous compounds such as DHEA and corticosterone, as well as xenobiotics including mestranol, β-naphthylamine, β-naphthol, and butylated hydroxyl anisole (BHA). pH-dependency and kinetic constants of these three enzymes were determined with DHEA, β-naphthol, and 17β-estradiol as substrates. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to examine the expression of these three new zebrafish SULTs at different developmental stages during embryogenesis, through larval development, and on to maturity.
- Published
- 2011
49. Purification and characterization of an NADH-rubredoxin oxidoreductase involved in the utilization of oxygen by Desulfovibrio gigas
- Author
-
Liang Chen, Ming-Yih Liu, Helena Santos, Jean LeGall, António V. Xavier, and Paula Fareleira
- Subjects
chemistry.chemical_classification ,biology ,Spectrum Analysis ,Cyanide ,p-Chloromercuribenzoic Acid ,biology.organism_classification ,Biochemistry ,Redox ,Molecular Weight ,Oxygen ,chemistry.chemical_compound ,Enzyme ,chemistry ,Oxidoreductase ,Rubredoxin ,Sulfites ,Desulfovibrio gigas ,Desulfovibrio ,NADH, NADPH Oxidoreductases ,Azide ,Chloromercuribenzoates ,Oxidation-Reduction ,Bacteria - Abstract
An NADH--rubredoxin oxidoreductase previously isolated from Desulfovibrio gigas [LeGall, J. (1968) Ann. Inst. Pasteur 114, 109-115] has now been fully purified and further characterized. It contains two subunits of 27 kDa and 32 kDa. With two mid-point redox potentials of -295 mV and -325 mV, this FMN- and FAD-containing protein can induce the specific reduction of D. gigas rubredoxin. In contrast, rubredoxins from the other Desulfovibrio species or desulforedoxin from D. gigas show very low reaction rates with the same enzyme. The phylogenetic significance of the narrow specificity of the enzyme toward the rubredoxin from the same organism is discussed. The purified enzyme has NADH oxidase activity with H2O2 as a final product of O2 reduction. The reaction is half-inhibited by 4.2 microM p-chloromercuribenzoate, whereas cyanide and azide are not significant inhibitors in this reaction. The role of this protein as a part of the enzymic equipment that allows the formation of ATP in the presence of oxygen from the degradation of carbon reserves is discussed.
- Published
- 1993
50. Isolation and Characterization of Flavoredoxin, a New Flavoprotein That Permits in Vitro Reconstitution of an Electron Transfer Chain from Molecular Hydrogen to Sulfite Reduction in the Bacterium Desulfovibrio gigas
- Author
-
Jean LeGall, Liang Chen, and Ming-Yih Liu
- Subjects
Hydrogenase ,Flavodoxin ,Stereochemistry ,Molecular Sequence Data ,Biophysics ,Cytochrome c Group ,Biochemistry ,Electron Transport ,Electron transfer ,Bacterial Proteins ,Sulfites ,Desulfovibrio gigas ,Amino Acid Sequence ,Molecular Biology ,Flavoproteins ,biology ,Chemistry ,Spectrum Analysis ,Cytochrome c ,Calcium-Binding Proteins ,Periplasmic space ,Electron transport chain ,Molecular Weight ,Bisulfite ,biology.protein ,Desulfovibrio ,Oxidation-Reduction ,Hydrogen - Abstract
A new FMN-containing flavoprotein isolated from Desulfovibrio gigas provided maximum coupling efficiency for the reduction of bisulfite from molecular H2. This protein, which is distinct from flavodoxin and for which the name flavoredoxin is proposed, is required for reconstitution of an electron transfer chain between hydrogenase and bisulfite reductase. A Ca(2+)-binding protein functions as a modulator in the presence of Ca2+ in the process. The finding of a membrane-bound cytochrome c with a molecular weight of 104,000 Da that is also active in this electron transfer chain provides an explanation for the energetic linkage between periplasmic and cytoplasmic proteins in this sulfate-reducing bacterium.
- Published
- 1993
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