59 results on '"QUAGLIARIELLO E"'
Search Results
2. ESR STUDIES OF THE SULPHYDRYL GROUPS OF THE MITOCHONDRIAL PHOSPHATE CARRIER BY MALEIMIDE SPIN LABELS
- Author
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BERTOLI, E., primary, STIPANI, I., additional, PALMIERI, F., additional, HOUSTEK, J., additional, SVOBODA, P., additional, MEGLI, F.M., additional, and QUAGLIARIELLO, E., additional
- Published
- 1983
- Full Text
- View/download PDF
3. INTRODUCTION
- Author
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Quagliariello, E., primary
- Published
- 1974
- Full Text
- View/download PDF
4. SOLUBILIZATION OF MYELIN PROTEINS BY DETERGENTS
- Author
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RICCIO, P., primary, SIMONE, S.M., additional, CIBELLI, G., additional, DE SANTIS, A., additional, BOBBA, A., additional, LIVREA, P., additional, and QUAGLIARIELLO, E., additional
- Published
- 1983
- Full Text
- View/download PDF
5. EFFECT OF CATIONS AND PH ON THE KINETICS OF UPTAKE OF METABOLITE ANIONS IN MITOCHONDRIA
- Author
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Quagliariello, E., primary, Meisner, H., additional, and Palmieri, F., additional
- Published
- 1973
- Full Text
- View/download PDF
6. Different recognition by clostripain of myelin basic protein in the lipid-free and lipid-bound forms.
- Author
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Liuzzi GM, Tamborra R, Ventola A, Bisaccia F, Quagliariello E, and Riccio P
- Subjects
- Animals, Cattle, Electrophoresis, Polyacrylamide Gel, Hydrolysis, Metalloendopeptidases metabolism, Protein Binding, Serine Endopeptidases metabolism, Cysteine Endopeptidases metabolism, Lipid Metabolism, Myelin Basic Protein metabolism
- Abstract
Different proteolytic enzymes were tested for their ability to degrade the myelin basic protein of the central nervous system, purified in two different forms, the lipid-free form and the lipid-bound form. As shown by SDS gel electrophoresis only clostripain, a thiol protease, was able to distinguish between the two MBPs since it degraded MBP only in the lipid-free form. The failure to degrade lipid-bound MBP by clostripain could not be ascribed to the presence of lipids, since the other proteolytic enzymes tested degraded both MBPs independently from lipids giving fragments with different size. These results may be related to different conformations of MBPs possibly relevant for the study of myelin structure and antigenic properties of the protein.
- Published
- 1996
- Full Text
- View/download PDF
7. Use of protease sensitivity to probe the conformations of newly synthesised mutant forms of mitochondrial aspartate aminotransferase.
- Author
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Azzariti A, Giannattasio S, Doonan S, Merafina RS, Marra E, and Quagliariello E
- Subjects
- Alanine, Animals, Aspartate Aminotransferases biosynthesis, Aspartate Aminotransferases metabolism, Cell-Free System, Kinetics, Mutagenesis, Site-Directed, Plasmids, Rats, Recombinant Fusion Proteins biosynthesis, Recombinant Fusion Proteins chemistry, Recombinant Fusion Proteins metabolism, Serine, Tetrahydrofolate Dehydrogenase chemistry, Tetrahydrofolate Dehydrogenase metabolism, Aspartate Aminotransferases chemistry, Cysteine, Mitochondria, Liver enzymology, Point Mutation, Pronase metabolism, Protein Conformation
- Abstract
Sensitivity to digestion with pronase has been used to show that the precursor form of mitochondrial aspartate aminotransferase, the form lacking the N-terminal presequence, that with a deletion of the first 9 residues and mutants of the mature enzyme in which residue Cys-166 is mutated to alanine or serine, all retain unfolded conformations after synthesis in a reticulocyte lysate. In the presence of lysed mitochondria the various forms of mitochondrial aspartate aminotransferase retained their susceptibilities to pronase in a way that mirrored the efficiencies with which they are imported into intact mitochondria. The results are interpreted as showing that the presequence of mitochondrial aspartate aminotransferase is not uniquely required for interaction with cytosolic factors required to maintain the newly synthesised protein in a form competent for interacting with, and being imported into, mitochondria.
- Published
- 1995
- Full Text
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8. Cumulative effects of mutations in newly synthesised mitochondrial aspartate aminotransferase on uptake into mitochondria.
- Author
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Marra E, Azzariti A, Giannattasio S, Doonan S, and Quagliariello E
- Subjects
- Alanine, Amino Acid Sequence, Animals, Aspartate Aminotransferases biosynthesis, Aspartate Aminotransferases genetics, Cysteine, Kinetics, Mutagenesis, Site-Directed, Protein Processing, Post-Translational, Recombinant Proteins biosynthesis, Recombinant Proteins metabolism, Serine, Aspartate Aminotransferases metabolism, Mitochondria metabolism, Point Mutation
- Abstract
Mutant genes were constructed which coded for the precursor form of mitochondrial aspartate aminotransferase in which residue cysteine 166 was mutated to either serine or alanine and for forms of the protein lacking both the presequence and residues 1-9 of the mature protein but carrying the same cysteine mutations. The protein products of all of these mutant genes were imported into mitochondria that had been added to the expression system but with varying degrees of efficiency. The results showed that the effects of mutation of cysteine 166 and of deletion of residues 1-9 of the mature protein on sequestration into mitochondria were essentially cumulative, suggesting that these parts of the protein are involved in distinct steps on the recognition/uptake pathway.
- Published
- 1995
- Full Text
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9. Glutamine transport in normal and acidotic rat kidney mitochondria.
- Author
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Atlante A, Passarella S, Minervini GM, and Quagliariello E
- Subjects
- Animals, Antiporters metabolism, Biological Transport, Glutamates metabolism, Hydrogen-Ion Concentration, In Vitro Techniques, Kinetics, Malates metabolism, Male, Mitochondria metabolism, Rats, Rats, Wistar, Acidosis metabolism, Glutamine metabolism, Kidney metabolism
- Abstract
Glutamine transport in both normal and acidotic rat kidney mitochondria was investigated using both isotopic techniques and by spectroscopic measurements in which glutamine metabolism was allowed to occur. Widely used criteria for demonstrating the occurrence of carrier-mediated transport were successfully applied in both cases. Three transport mechanisms were found to occur, namely glutamine uniport, active only during acidosis and glutamine/glutamate and glutamine/malate antiports, active in both normal and acidotic mitochondria. Efflux of glutamate, via a glutamate/OH- translocator, following glutamine uptake by mitochondria was experimentally ruled out. Glutamine uniport in acidotic mitochondria and glutamine/glutamate and glutamine/malate antiports in both normal and acidotic mitochondria were investigated in detail: differences found in Km and Vmax values, in pH and temperature dependence, and in the pattern of inhibitor sensitivity of glutamine transport demonstrated the existence of five different translocators whose activities were found to fit with the physiological requirements of renal ammoniogenesis.
- Published
- 1994
- Full Text
- View/download PDF
10. Increase of both transcription and translation activities following separate irradiation of the in vitro system components with He-Ne laser.
- Author
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Vacca RA, Marra E, Quagliariello E, and Greco M
- Subjects
- Animals, Aspartate Aminotransferases genetics, DNA-Directed RNA Polymerases metabolism, Helium, Neon, RNA, Messenger biosynthesis, Rabbits, Reticulocytes metabolism, Spectrometry, Fluorescence, Spectrophotometry, Tetrahydrofolate Dehydrogenase genetics, Lasers, Protein Biosynthesis radiation effects, Transcription, Genetic radiation effects
- Abstract
To gain insight into the mechanism by which cell irradiation with low power continuous wave He-Ne laser (632.8 nm) causes a general stimulation of biosynthetic properties, separate components of transcription and translation systems were irradiated (energy dose 2 Joules/cm2; laser power 12 mW) with measurements made of in vitro RNA and protein synthesis. In addition, all tested components were investigated with respect to influence of laser irradiation on their conformation, as spectroscopically monitored. In all cases an increase in both transcription and translation activities was found with a significant change in absorbance/fluorescence spectra.
- Published
- 1994
- Full Text
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11. Spectroscopic study of hydroxyproline transport in rat kidney mitochondria.
- Author
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Atlante A, Passarella S, and Quagliariello E
- Subjects
- Animals, Biological Transport, Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone pharmacology, Kinetics, Male, Mitochondria drug effects, Models, Biological, NAD metabolism, NADP metabolism, Oxidation-Reduction, Rats, Rats, Wistar, Spectrometry, Fluorescence methods, Spectrophotometry, Ultraviolet methods, Succinates pharmacology, Hydroxyproline metabolism, Kidney metabolism, Mitochondria metabolism
- Abstract
Hydroxyproline uptake by rat kidney mitochondria is here first shown by monitoring the reduction of the intramitochondrial pyridine nucleotides which occurs as a result of metabolism of imported hydroxyproline via hydroxyproline oxidase and 3-hydroxy-pyrroline-5-carboxylate dehydrogenase. Widely used criteria for demonstrating the occurrence of carrier-mediated transport were applied to this process. Hydroxyproline uptake shows saturation features (Km and Vmax values, measured at 20 degrees C and at pH 7.20, were found to be about 1.4 mM and 5 nmoles/min x mg mitochondrial protein, respectively) and proves to be inhibited by the impermeable compound phenylsuccinate, but insensitive to externally added methylglutamate. Difference found in the Km and Vmax values, a different inhibitor sensitivity and the failure of hydroxyproline to cause efflux of glutamate from the mitochondria show that hydroxyproline enters mitochondria by means of a translocator different from those which transport proline.
- Published
- 1994
- Full Text
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12. The N-terminal region of mature mitochondrial aspartate aminotransferase can direct cytosolic dihydrofolate reductase into mitochondria in vitro.
- Author
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Giannattasio S, Azzariti A, Marra E, and Quagliariello E
- Subjects
- Aspartate Aminotransferases chemistry, Cell Compartmentation, Cytosol enzymology, In Vitro Techniques, Recombinant Fusion Proteins, Structure-Activity Relationship, Tetrahydrofolate Dehydrogenase chemistry, Aspartate Aminotransferases metabolism, Mitochondria enzymology, Tetrahydrofolate Dehydrogenase metabolism
- Abstract
Two fused genes were constructed which encode for two chimeric proteins in which either 10 or 191 N-terminal amino acids of mature mitochondrial aspartate aminotransferase had been attached to the entire polypeptide chain of cytosolic dihydrofolate reductase. The precursor and mature form of mitochondrial aspartate aminotransferase, dihydrofolate reductase and both chimeric proteins were synthesized in vitro and their import into isolated mitochondria was studied. Both chimeric proteins were taken up by isolated organelles, where they became protease resistant, thus indicating the ability of the N-terminal portion of the mature moiety of the precursor of mitochondrial aspartate aminotransferase to direct cytosolic dihydrofolate reductase into mitochondria.
- Published
- 1994
- Full Text
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13. Proline transport in rat kidney mitochondria.
- Author
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Atlante A, Passarella S, Pierro P, and Quagliariello E
- Subjects
- Animals, Biological Transport drug effects, Carbon Radioisotopes, Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone pharmacology, Carrier Proteins metabolism, Glutamates metabolism, Glutamic Acid, Hydrogen-Ion Concentration, Kidney ultrastructure, Kinetics, Male, Mersalyl pharmacology, NAD pharmacology, Rats, Rats, Wistar, Temperature, Amino Acid Transport Systems, Neutral, Kidney metabolism, Mitochondria metabolism, Proline metabolism
- Abstract
Proline transport in rat kidney mitochondria was investigated both by using isotopic techniques and by spectroscopic measurements, in which proline metabolism was essentially allowed to occur. Widely used criteria for demonstrating the occurrence of carrier-mediated transport were successfully applied in both cases. Differences found in the Km and Vmax values, in pH and temperature dependence of proline transport, and in the inhibitor sensitivity demonstrate the existence of two separate translocators for proline in rat kidney mitochondria, i.e., the proline uniporter and the proline/glutamate antiporter. Efflux of glutamate via glutamate/OH- translocator following proline uptake by mitochondria was experimentally ruled out. Discussion is also made of the possible role of such translocators in proline metabolism and in the putative proline/glutamate shuttle.
- Published
- 1994
- Full Text
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14. Lactate dehydrogenase isoenzyme patterns in blood cells from histiocytosis X children.
- Author
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Perlino E, Marra E, Maenza S, de Terlizzi M, Coppola BC, Santostasi T, and Quagliariello E
- Subjects
- Child, Child, Preschool, Female, Follow-Up Studies, Humans, Infant, Isoenzymes, Male, Prognosis, Histiocytosis, Langerhans-Cell enzymology, L-Lactate Dehydrogenase blood, Leukocytes, Mononuclear enzymology
- Abstract
To find a clinical assay for histiocytosis X (HX) diagnosis, measurements were made of both activity and isoenzyme distribution of lactate dehydrogenase (LDH; EC 1.1.1.27) from the blood cells of 6 acute phase and 9 remission patients. A significant increase in the LDH activity measured in the monocytes and lymphocytes isolated from the blood of the acute phase patients was found. The increased activity was due to an enhancement of the normal pattern of LDH isoenzymes in these cells and not to a change in isoenzyme distribution. No increase was found in monocyte LDH isoenzymes from the patients in remission.
- Published
- 1993
- Full Text
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15. Decreased cytochrome oxidase activity and changes in phospholipids in heart mitochondria from hypothyroid rats.
- Author
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Paradies G, Ruggiero FM, Dinoi P, Petrosillo G, and Quagliariello E
- Subjects
- Animals, Hypothyroidism chemically induced, Hypothyroidism enzymology, Intracellular Membranes chemistry, Intracellular Membranes metabolism, Kinetics, Male, Membrane Lipids chemistry, Mitochondria, Heart enzymology, Phospholipids chemistry, Propylthiouracil, Rats, Rats, Wistar, Reference Values, Thermodynamics, Triiodothyronine pharmacology, Electron Transport Complex IV metabolism, Hypothyroidism metabolism, Membrane Lipids metabolism, Mitochondria, Heart metabolism, Oxygen Consumption, Phospholipids metabolism
- Abstract
The effect of hypothyroidism on kinetic characteristics of cytochrome oxidase in rat heart mitochondria was studied. Mitochondrial preparations from control and hypothyroid rats had equivalent Km values for cytochrome c, while the maximal activity of the oxidase was significantly decreased (more than 30%) in mitochondrial preparations from hypothyroid rats. This decrease is associated to a parallel decrease in state 3 respiration. The cytochrome aa3 content was slightly decreased (by around 15%) in mitochondria from hypothyroid rats. The Arrhenius plot characteristics differ for cytochrome oxidase activity in mitochondria from hypothyroid rats as compared with control rats in that the breakpoint of the biphasic plot is shifted to a higher temperature. Cardiolipin content was markedly decreased in the mitochondrial membrane from hypothyroid rats. No alterations were found in the pattern of cardiolipin fatty acid distribution of mitochondrial membrane from control and hypothyroid rats. The effects of the hypothyroid state on the activity of cytochrome oxidase, on cytochrome aa3 levels, and on cardiolipin contents were completely reversed by following the treatment of hypothyroid rats with thyroid hormone. The results support the conclusion that the depressed mitochondrial cytochrome oxidase activity in the hypothyroid state is due, at least in part, to a decrease in the cardiolipin content of the mitochondrial inner membrane.
- Published
- 1993
- Full Text
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16. Activation of mitochondrial DNA replication by He-Ne laser irradiation.
- Author
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Vacca RA, Marra E, Quagliariello E, and Greco M
- Subjects
- Animals, DNA, Mitochondrial isolation & purification, Deoxyadenine Nucleotides metabolism, Electrophoresis, Agar Gel, Kinetics, Male, Mitochondria, Liver radiation effects, Phosphorus Radioisotopes, Rats, Rats, Wistar, DNA Replication radiation effects, DNA, Mitochondrial biosynthesis, Lasers, Mitochondria, Liver metabolism
- Abstract
To gain further insight into the effect of He-Ne laser irradiation on the mitochondrial biosynthetic apparatus, DNA synthesis was measured in mitochondria, mitoplasts and mitochondrial matrix fraction irradiated with low power continuous wave He-Ne laser (energy dose 5 Joules/cm2; laser power 12 mW). As a result of irradiation, the amount of alpha-[32P]dATP incorporated in acid insoluble materials was found to increase. Electrophoretic analysis of in vitro synthesised DNA purified from mitochondria, mitoplasts and matrix fraction shows an increase of 50-60% of DNA synthesis in the irradiated samples. These data show that He-Ne laser stimulates the replication of mitochondrial DNA in both intact organelles and soluble matrix fraction, thus suggesting an interaction of laser light with matrix soluble molecule/s.
- Published
- 1993
- Full Text
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17. Flavin adenine dinucleotide synthesis in isolated rat liver mitochondria caused by imported flavin mononucleotide.
- Author
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Barile M, Passarella S, Bertoldi A, and Quagliariello E
- Subjects
- Animals, Biological Transport, In Vitro Techniques, Rats, Flavin Mononucleotide metabolism, Flavin-Adenine Dinucleotide biosynthesis, Mitochondria, Liver metabolism
- Abstract
Evidence is given in this paper that externally added flavin mononucleotide (FMN) induces flavin adenine dinucleotide synthesis in isolated rat liver mitochondria, as shown by fluorimetric, chromatographic, and enzymatic assays. FMN association with mitochondria is a process with hyperbolic features that is sensitive to externally added mersalyl.
- Published
- 1993
- Full Text
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18. Import of mutant forms of mitochondrial aspartate aminotransferase into isolated mitochondria.
- Author
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Giannattasio S, Marra E, Vacca RA, Iannace G, and Quagliariello E
- Subjects
- Amino Acid Sequence, Base Sequence, Biological Transport, Cell-Free System, Kinetics, Molecular Sequence Data, Oligodeoxyribonucleotides, Plasmids, Restriction Mapping, Sequence Deletion, Aspartate Aminotransferases genetics, Aspartate Aminotransferases metabolism, Mitochondria enzymology, Mutagenesis, Site-Directed
- Abstract
To gain some insight into the role played by certain protein domains in the import of mitochondrial aspartate aminotransferase in isolated mitochondria, three protein mutants were constructed by using the plasmid pOTS-mAspAT, which contains the nucleotide sequence encoding for the mature form of this enzyme. Two mutant proteins in which Cys-166 was substituted with either serine or alanine and another protein lacking the nine N-terminal amino acids were all synthesized in a cell-free transcription/translation system. Comparison was made among the newly synthesized mutant proteins and the newly synthesized wild type aspartate aminotransferase with respect to their capability to enter mitochondria. All the mutant proteins proved to be able to enter mitochondria even though with a lower efficiency than the wild type enzyme. Interestingly the thiol reagent mersalyl proved to inhibit import of both wild type enzyme and serine mutant, whereas import of alanine mutant was found to be insensitive to mersalyl, thus showing that Cys-166 is the unique -SH group involved in import. Import of mitochondrial aspartate aminotransferase by mitochondria is shown to involve certain protein domains present in the mature protein, two of them being the Cys-166 and the N-terminal regions.
- Published
- 1992
- Full Text
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19. Identification of water-soluble proteases in myelin preparations.
- Author
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Liuzzi GM, Ventola A, Riccio P, and Quagliariello E
- Subjects
- Animals, Brain ultrastructure, Cattle, Cell Fractionation, Centrifugation, Density Gradient, Electrophoresis, Polyacrylamide Gel, Endopeptidases isolation & purification, Molecular Weight, Myelin Basic Protein isolation & purification, Myelin Sheath ultrastructure, Brain enzymology, Endopeptidases metabolism, Myelin Basic Protein metabolism, Myelin Sheath enzymology
- Abstract
Sodium chloride extracts obtained from purified bovine brain myelin were found to contain proteolytic activity capable of degrading isolated myelin basic protein as assessed by SDS gel electrophoresis. Using gels copolymerized with gelatin as substrate, two bands at about 54 and 117-125 KDa, respectively, were detected. Activity corresponding to the 54 KDa band was inhibited by zinc. Data presented in this article suggest that proteolytic activity can be released from the myelin sheath in water-soluble form and recognize MBP as substrate.
- Published
- 1992
- Full Text
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20. Effect of MNU on the methylation pattern of hepatic DNA during compensatory cell proliferation.
- Author
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Kanduc D, Aresta A, Quagliariello E, and Farber E
- Subjects
- Animals, DNA isolation & purification, Kinetics, Liver cytology, Liver drug effects, Liver Regeneration, Male, Methylation, Rats, Rats, Inbred Strains, Cell Division drug effects, DNA metabolism, Liver metabolism, Methylnitrosourea pharmacology
- Abstract
We have used the initiation-promotion model of MNU-induced hepatocarcinogenesis to test the hypothesis that alteration of the methylation status of DNA cytosines could be involved in the initiation of carcinogenesis. In fact cell proliferation plays a fundamental role in the initiation of liver carcinogenesis and hepatocytes in the S phase are more sensitive towards MNU initiation than at other times in the cycle. The molecular mechanisms involved in these processes, however, are still poorly understood and it seemed of value to monitor the DNA methylation status in this system. The results obtained indicate that MNU hepatocarcinogenic action might consist also of the inhibition of DNA hypomethylation biologically associated with cell proliferation.
- Published
- 1992
- Full Text
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21. Pyruvate/malate antiporter in rat liver mitochondria.
- Author
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Atlante A, Passarella S, and Quagliariello E
- Subjects
- Animals, Citrates metabolism, Kinetics, Mitochondria, Liver drug effects, Models, Biological, Oxaloacetates metabolism, Rats, Rotenone pharmacology, Antiporters, Carrier Proteins metabolism, Malates metabolism, Mitochondria, Liver metabolism, Pyruvates metabolism
- Abstract
To gain some insight into the process by which both acetylCoA and NADPH, needed for fatty acid synthesis, are obtained, in the cytosol, from the effluxed intramitochondrial citrate, via citrate lyase and malate dehydrogenase plus malic enzyme respectively, the capability of externally added pyruvate to cause efflux of malate from rat liver mitochondria was tested. The occurrence of a pyruvate/malate translocator is here shown: pyruvate/malate exchange shows saturation features (Km and Vmax values, measured at 20 degrees C and at pH 7.20, were found to be about 0.25 mM and 2.7 nmoles/min x mg mitochondrial protein, respectively) and is inhibited by certain impermeable compounds. This carrier, together with the previously reported tricarboxylate and oxodicarboxylate translocators proved to allow for citrate and oxaloacetate efflux due to externally added pyruvate.
- Published
- 1992
- Full Text
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22. The in vitro-synthesized precursor and mature mitochondrial aspartate aminotransferase share the same import pathway in isolated mitochondria.
- Author
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Giannattasio S, Marra E, Abruzzese MF, Greco M, and Quagliariello E
- Subjects
- Animals, Aspartate Aminotransferases antagonists & inhibitors, Aspartate Aminotransferases isolation & purification, Binding, Competitive, Biological Transport, Carbonyl Cyanide m-Chlorophenyl Hydrazone analogs & derivatives, Carbonyl Cyanide m-Chlorophenyl Hydrazone pharmacology, Cell Fractionation, Cell-Free System, Male, Mitochondria, Liver drug effects, Plasmids, Protein Precursors genetics, Rats, Rats, Inbred Strains, Substrate Specificity, Aspartate Aminotransferases biosynthesis, Mitochondria, Liver enzymology, Protein Precursors biosynthesis
- Abstract
Both the precursor and the mature form of mitochondrial aspartate aminotransferase were synthesized in a cell-free coupled transcription/translation system directed by the recombinant expression plasmid pOTS-pmAspAT and pOTS-mAspAT, respectively. Both newly synthesized forms of the protein were imported into isolated mitochondria, with the precursor correctly processed to the mature form. In both cases the import process showed resistance to externally added pronase and was abolished in mitochondria treated with the uncoupler carbonyl cyanide m-chlorophenylhydrazone. Moreover the imported products showed the same intramitochondrial localization as judged by a subfractionation procedure. In both cases import was time dependent and was completed in about 15 min. Finally a competitive inhibition of the import of the precursor of aspartate aminotransferase was found due to externally added purified aspartate aminotransferase.
- Published
- 1991
- Full Text
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23. On the spontaneous adherence of myelin basic protein to T lymphocytes.
- Author
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Bobba A, Munno I, Greco B, Pellegrino NM, Riccio P, Jirillo E, and Quagliariello E
- Subjects
- Animals, Antigens, CD analysis, Cattle, Cells, Cultured, Humans, Protein Binding, T-Lymphocyte Subsets metabolism, Myelin Basic Protein metabolism, T-Lymphocytes metabolism
- Abstract
We have applied a double tagging system in order to study whether purified myelin basic protein is able to adhere to normal human peripheral T lymphocytes without the need to purify cells. Evaluation of myelin basic protein adherence to peripheral blood mononuclear cells was determined with biotinylated myelin basic protein and fluoresceinated avidin, and lymphocyte population was identified by the corresponding phycoerythrinated monoclonal antibody. The observed adherence of myelin basic protein to T lymphocytes was found to depend on protein conformation.
- Published
- 1991
- Full Text
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24. Biochemical properties of blood cells from histiocytosis X patients.
- Author
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Perlino E, Marra E, Petragallo VA, Quagliariello E, de Terlizzi M, Santostasi T, and Ceci A
- Subjects
- Blood Proteins biosynthesis, Blood Proteins chemistry, Child, Child, Preschool, Female, Granulocytes enzymology, Humans, Infant, Lymphocytes chemistry, Lymphocytes enzymology, Male, Monocytes chemistry, Monocytes enzymology, Erythrocytes enzymology, Histiocytosis, Langerhans-Cell metabolism, L-Lactate Dehydrogenase blood, Leukocytes enzymology, Malate Dehydrogenase blood
- Published
- 1991
- Full Text
- View/download PDF
25. Transitory DNA hypomethylation during liver cell proliferation induced by a single dose of lead nitrate.
- Author
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Kanduc D, Rossiello MR, Aresta A, Cavazza C, Quagliariello E, and Farber E
- Subjects
- Animals, Cell Division drug effects, DNA drug effects, Deoxycytidine analogs & derivatives, Deoxycytidine analysis, Kinetics, Liver drug effects, Liver metabolism, Male, Methylation, Organ Size drug effects, Rats, Rats, Inbred Strains, Reference Values, Restriction Mapping, Time Factors, DNA metabolism, Lead pharmacology, Liver cytology, Nitrates pharmacology
- Abstract
In the present study we have examined the effect of a single dose of the mitogen lead nitrate (75 mumols/kg body wt) on the methylation status of hepatic DNA in male Wistar rats. It was found that extensive hypomethylation of hepatic DNA occurs in mitogen-treated rat liver. This effect could be seen as early as 12 h after metal treatment and parallels the changes in liver weight. Probing with the methylation-sensitive enzymes HpaII, MspI, and HaeIII confirmed HPLC analyses and showed that methylation at these sites was affected by lead treatment. DNA hypomethylation has already been found in regenerating rat liver and in hepatic (pre)malignant lesions when compared to normal nondividing liver. Thus the lowering of the DNA 5-methylcytosine content appears to be a property characteristic of cellular proliferation, regardless of whether it is caused by partial hepatectomy, carcinogen treatments, or mitogen administration.
- Published
- 1991
- Full Text
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26. Spin labeling of calcium-dependent phospholipid-binding proteins.
- Author
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Megli FM, De Lisi A, and Quagliariello E
- Subjects
- Animals, Calcium-Binding Proteins metabolism, Cattle, Chromatography, Ion Exchange, Electron Spin Resonance Spectroscopy, Iodoacetamide, Temperature, Calcium metabolism, Calcium-Binding Proteins analysis, Phospholipids metabolism
- Abstract
Bovine lung annexins p32 and p34 were spin labeled with an iodoacetamidoproxyl spin label, a reagent that reportedly couples with protein methionine residues. Labeling conditions and stoichiometry were studied with the radiolabeled analogue [1-14C]iodoacetamide. As judged by this method, carboxamidomethylation of both p32 and p34 occurred up to a 0.7 mol ratio after 60 h of reaction at 37 degrees C and at pH 4. The two proteins retained Ca2(+)-dependent phospholipid-binding ability both in radiolabeled and in spin-labeled forms. Electron resonance spectra of spin-labeled p32 and p34 showed the features of a partially immobilized spin probe, with rotational correlation time values of 1.15 and 1.25 ns, respectively, which definitely indicate successful spin labeling. Quantitation of ESR spectra by computer double integration indicated 70% spin labeling of both proteins, as anticipated by radiolabeling. The use of spin-labeled p32 and p34 in the study of Ca2(+)-dependent interaction of annexins with biomembranes is proposed.
- Published
- 1990
- Full Text
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27. Thiamine pyrophosphate uptake into isolated rat liver mitochondria.
- Author
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Barile M, Passarella S, and Quagliariello E
- Subjects
- Animals, Biological Transport, Cytosol metabolism, Intracellular Membranes metabolism, Male, Rats, Rats, Inbred Strains, Thiamine metabolism, Thiamine pharmacology, Thiamine Pyrophosphate pharmacology, Mitochondria, Liver metabolism, Thiamine Pyrophosphate metabolism
- Abstract
The fact that thiamine pyrophosphate is synthesized in cytosol necessitates its uptake into mitochondria. The ability of mitochondria to take up externally added thiamine pyrophosphate was investigated by measuring the intramitochondrial thiamine pyrophosphate content using an enzymatic method. Thiamine pyrophosphate uptake by isolated rat liver mitochondria was found to occur in a time- and temperature-dependent manner. Uptake shows saturation characteristics with Km and Vmax values equal to about 20 microM and 700 pmol/min x mg protein, respectively, and is inhibited by certain nonpenetrating compounds. The inhibition of thiamine uptake by thiamine pyrophosphate and the efflux of endogenous thiamine pyrophosphate, caused by externally added thiamine, suggest the existence of a thiamine pyrophosphate/thiamine antiporter which could play an active role in the turnover of intramitochondrial thiamine pyrophosphate linked enzymes.
- Published
- 1990
- Full Text
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28. Effect of aging and acetyl-L-carnitine on the lipid composition of rat plasma and erythrocytes.
- Author
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Ruggiero FM, Cafagna F, Gadaleta MN, and Quagliariello E
- Subjects
- Animals, Cholesterol blood, Cholesterol metabolism, Erythrocytes drug effects, Phospholipids blood, Phospholipids metabolism, Rats, Rats, Inbred Strains, Acetylcarnitine pharmacology, Aging, Carnitine analogs & derivatives, Erythrocytes metabolism, Lipids blood, Plasma metabolism
- Abstract
The effect of aging and treatment with acetyl-L-carnitine on the lipid composition of rat plasma and erythrocytes was studied. It was found that aging increases the levels of free and esterified cholesterol. Fatty acid patterns in the plasma of aged rats show remarkable alterations when compared with control rats. These changes reverted to normal after three hours of acetyl-L-carnitine treatment. No significant differences in the erythrocyte lipid pattern of young and aged rats were observed. This study provides the first proof that acetyl-L-carnitine probably acts by lowering free and esterified cholesterol and arachidonic acid (20:4) levels in the plasma.
- Published
- 1990
- Full Text
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29. Certain N-terminal peptides inhibit uptake of mature aspartate aminotransferase by isolated mitochondria.
- Author
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Barile M, Giannattasio S, Marra E, Passarella S, Pucci P, Sannia G, and Quagliariello E
- Subjects
- Amino Acid Sequence, Animals, Biological Transport, Cattle, In Vitro Techniques, Kinetics, Mitochondria, Heart drug effects, Molecular Sequence Data, Peptides pharmacology, Aspartate Aminotransferases metabolism, Cyanogen Bromide pharmacology, Mitochondria, Heart enzymology
- Abstract
To gain insight into the uptake of mature aspartate aminotransferase by isolated mitochondria, the capability of certain cyanogen bromide peptides from mature beef heart mitochondrial aspartate aminotransferase to inhibit enzyme uptake was kinetically tested. N-terminal peptides (1-9 and 10-31) proved to inhibit the rate of aspartate aminotransferase uptake respectively in purely competitive and non-competitive ways, whereas other peptides distal from the N-terminus (203-217, 321-327 and 328-353) were found to be completely ineffective.
- Published
- 1990
- Full Text
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30. The effect of sulfhydryl group reagents on the permeation of mitochondrial aspartate aminotransferase into mitochondria in vitro.
- Author
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Marra E, Passarella S, Doonan S, Saccone C, and Quagliariello E
- Subjects
- Animals, Biological Transport drug effects, Cysteine pharmacology, Ethylmaleimide pharmacology, Kinetics, Mersalyl pharmacology, Mitochondria, Liver drug effects, Permeability, Rats, Aspartate Aminotransferases metabolism, Mitochondria, Liver enzymology, Sulfhydryl Reagents pharmacology
- Published
- 1979
- Full Text
- View/download PDF
31. Oxaloacetate permeation in rat kidney mitochondria: pyruvate/oxaloacetate and malate/oxaloacetate translocators.
- Author
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Passarella S, Atlante A, and Quagliariello E
- Subjects
- Adenosine Triphosphate metabolism, Animals, Biological Transport, Active, Brain metabolism, Gluconeogenesis, Kinetics, Mitochondria metabolism, Mitochondria, Heart metabolism, Mitochondria, Liver metabolism, Permeability, Pyruvic Acid, Rats, Kidney metabolism, Malates metabolism, Oxaloacetates metabolism, Pyruvates metabolism
- Abstract
The mechanism of oxaloacetate efflux from rat kidney mitochondria has been investigated in view of its possible role both in gluconeogenesis and in transferring cytosolic reducing equivalents into mitochondria. Thus reconstruction of the malate/oxaloacetate shuttle made possible by the oxaloacetate carrier has been made. Moreover the existence of a separate translocator able to allow a bidirectional alpha-cyanocinnamate-insensitive pyruvate/oxaloacetate exchange has been ascertained. This carrier is specific of gluconeogenetic organs in particularly of kidney, where it shows a marked affinity for pyruvate (Km = 0.45 mM and Vmax = 38 nmoles oxaloacetate effluxed/min X mg mitochondrial protein at 20 degrees C). Some features of both pyruvate/oxaloacetate and malate/oxaloacetate exchanges are also described.
- Published
- 1985
- Full Text
- View/download PDF
32. "In vivo" (35S)methionine interaction with rat liver tRNA.
- Author
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Kanduc D, Rossiello MR, Ranieri T, and Quagliariello E
- Subjects
- Animals, DNA metabolism, Magnetic Resonance Spectroscopy, Rats, Spectrophotometry, Ultraviolet, Liver physiology, Methionine metabolism, RNA, Transfer metabolism, Sulfur
- Abstract
As part of a study to characterize the methionine role in tumorigenesis, we report that methionine sulfur interacts with rat liver tRNA "in vivo" (35S) radioactivity remained associated to the nucleic acid after a number of treatments, including tRNA deacylation. Similar data were obtained after administration of (methyl-3H) methionine, while no comparable tRNA labelling was detected when the aminoacid labelled in the aliphatic chain was given. Hplc analysis of (35S) tRNA enzymic hydrolysate showed two unidentified UV-absorbing radioactive peaks. NMR spectra of these two peaks did not reveal any thiomethyl group.
- Published
- 1989
- Full Text
- View/download PDF
33. Increase in RNA and protein synthesis by mitochondria irradiated with helium-neon laser.
- Author
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Greco M, Guida G, Perlino E, Marra E, and Quagliariello E
- Subjects
- Animals, Helium, Kinetics, Methionine metabolism, Mitochondria, Liver metabolism, Neon, Protein Biosynthesis, RNA biosynthesis, Rats, Uridine Triphosphate metabolism, Lasers, Mitochondria, Liver radiation effects, Proteins radiation effects, RNA radiation effects
- Abstract
To gain further insight into the mechanism of cell photostimulation by laser light, both RNA and protein synthesis were measured in mitochondria irradiated with the low power continuous wave He-Ne laser (Energy dose: 5 Joules/cm2). Following mitochondrial irradiation, both the rate and amount of incorporation of alpha-[32P]UTP and L-[35S]methionine, used to monitor RNA and protein synthesis respectively, proved to increase. Electrophoretic analysis made of the synthesis products clearly shows that He-Ne laser irradiation stimulates the synthesis of all mitochondrial transcription and translation products.
- Published
- 1989
- Full Text
- View/download PDF
34. DNA hypomethylation in ethionine-induced rat preneoplastic hepatocyte nodules.
- Author
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Kanduc D, Ghoshal A, Quagliariello E, and Farber E
- Subjects
- Animals, Deoxycytidine analogs & derivatives, Deoxycytidine analysis, Liver drug effects, Male, Methylation, Precancerous Conditions chemically induced, Rats, Rats, Inbred F344, Reference Values, DNA drug effects, Ethionine toxicity, Liver pathology, Liver Neoplasms, Experimental pathology, Precancerous Conditions pathology
- Abstract
DNA from hepatocyte nodules induced in rats with dietary DL-ethionine and from the surrounding non-nodular liver contained less 5-methyldeoxycytidine per deoxycytidine when compared with that from normal adult liver. The degree of apparent hypomethylation, 37% in nodules and 20% in the surrounding liver, decreased somewhat (29% and 16% respectively) at 2 weeks after terminating the exposure to ethionine. Nodules and surrounding liver, like normal liver, responded to partial hepatectomy with a decrease in the 5-methyldeoxycytidine level at 24 hrs and a return to the level at the time of partial hepatectomy by 38 hrs. These findings indicate the need for careful control of cell proliferation in comparing the levels of a post-replicative DNA modification, methylation, in proliferating and non-proliferating cell populations. These findings also suggest that a portion of the hypomethylation in preneoplastic nodules may be due to a bona fide decrease in the level of cytosine methylation in the parental strand of DNA. This hypomethylation could be one basis for the altered gene expression in hepatocyte nodules, possible precursors for liver cancer.
- Published
- 1988
- Full Text
- View/download PDF
35. Myelin basic protein ability to organize lipid bilayers: structural transition in bilayers of lysophosphatidylcholine micelles.
- Author
-
Riccio P, Masotti L, Cavatorta P, De Santis A, Juretic D, Bobba A, Pasquali-Ronchetti I, and Quagliariello E
- Subjects
- Animals, Cattle, Cetrimonium, Cetrimonium Compounds, Chromatography, Gel, Electrophoresis, Polyacrylamide Gel, Lysophosphatidylcholines metabolism, Micelles, Microscopy, Electron, Lipid Bilayers metabolism, Myelin Basic Protein metabolism
- Abstract
Myelin basic protein isolated by a single step with the cationic detergent cethyltrimethylammonium bromide in a lipid-bound form is able to induce structural transition of lysophosphatydilcholine micelles into multi-laminar vesicles. This finding, observed through electron microscopy, is discussed in the light of the assumed ability of the basic protein to organize myelin lipids.
- Published
- 1986
- Full Text
- View/download PDF
36. Metabolite transport in rat kidney mitochondria: ornithine/phosphate translocator.
- Author
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Passarella S, Atlante A, and Quagliariello E
- Subjects
- Animals, Biological Transport drug effects, Fluorometry, Glutamates metabolism, Glutamic Acid, Kinetics, Malates metabolism, Male, Mersalyl pharmacology, NAD metabolism, NADP metabolism, Ornithine pharmacology, Oxidation-Reduction, Praseodymium pharmacology, Rats, Rats, Inbred Strains, Spectrophotometry, Carrier Proteins metabolism, Kidney metabolism, Membrane Transport Proteins, Mitochondria metabolism, Ornithine metabolism, Phosphates metabolism
- Abstract
Ornithine uptake by rat kidney mitochondria is here first shown by monitoring the reduction of the intramitochondrial pyridine nucleotides which occurs as a result of metabolism of imported ornithine via ornithine aminotransferase and 1-pyrroline-carboxylate dehydrogenase. Ornithine uptake shows saturation features (Km and Vmax values, measured at 20 degrees C and at pH 7.20, were found to be about 0.85 mM and 23 nmoles/min x mg protein, respectively) and proves to be inhibited by D-ornithine, inorganic phosphate, praseodimium chloride and mersalyl. Neither malate nor glutamate, but phosphate was found to exchange with ornithine. Phosphate efflux caused by externally added ornithine was shown both as revealed by a c colorimetric assay and as continuously monitored by measuring extramitochondrial reduction of NAD+ in the presence of glyceraldehyde-3-phosphate, glyceraldehyde-3-phosphate dehydrogenase, ADP and 3-phosphoglycerate kinase. The role of ornithine carrier in kidney metabolism will also be discussed.
- Published
- 1989
- Full Text
- View/download PDF
37. The transport of oxaloacetate in isolated mitochondria.
- Author
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Passarella S, Palmieri F, and Quagliariello E
- Subjects
- Animals, Ketoglutaric Acids metabolism, Kinetics, Malates pharmacology, Malonates pharmacology, Mersalyl pharmacology, Mitochondria, Liver drug effects, Mitochondria, Liver metabolism, Mitochondria, Muscle metabolism, Myocardium, Phosphates metabolism, Rats, Succinates pharmacology, Tricarboxylic Acids pharmacology, Mitochondria metabolism, Oxaloacetates metabolism
- Published
- 1977
- Full Text
- View/download PDF
38. A general method for phospholipid polar head spin labeling. Synthesis of diphosphatidylglycerol-2(2' 2', 5', 5',-tetramethylpyrroline-N-oxide) carboxylate.
- Author
-
Landriscina C, Megli FM, and Quagliariello E
- Subjects
- Chemical Phenomena, Chemistry, Chromatography, Thin Layer, Electron Spin Resonance Spectroscopy, Methods, Molecular Conformation, Phosphatidylglycerols, Pyrroles, Spin Labels
- Published
- 1976
- Full Text
- View/download PDF
39. Fumarate permeation in rat heart mitochondria.
- Author
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Passarella S, Fasano E, Carrieri S, and Quagliariello E
- Subjects
- Animals, Biological Transport, Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone pharmacology, Fumarates pharmacology, Kinetics, Mitochondria, Heart drug effects, Mitochondrial Swelling drug effects, Phosphates metabolism, Phosphates pharmacology, Rats, Fumarates metabolism, Mitochondria, Heart metabolism
- Published
- 1979
- Full Text
- View/download PDF
40. Quantitative analysis of lymphocyte-Salmonella interaction and effect of lymphocyte irradiation by Helium-Neon laser.
- Author
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Passarella S, Casamassima E, Quagliariello E, Caretto G, and Jirillo E
- Subjects
- Binding Sites, Helium, Humans, Kinetics, Neon, Lasers, Lymphocytes metabolism, Salmonella metabolism
- Abstract
A model system has been developed to quantitatively investigate bacteria-cell interaction using a rough mutant of Salmonella and human peripheral blood lymphocytes. The effect of lymphocyte irradiation by low-power continuous wave Helium-Neon laser has been investigated since laser therapy in wound and decoubitous ulcer healing could involve the lymphoid cell function. Helium-Neon laser irradiation is shown here to enhance the adherence of Salmonella to lymphocytes. In particular, changes in newly defined binding parameters show that laser irradiation increases the frequency of binding-lymphocytes, the affinity of Salmonella for lymphocytes and the number of lymphocyte receptor sites as well.
- Published
- 1985
- Full Text
- View/download PDF
41. Short-term stimulation of lipogenesis by triiodothyronine in maintenance cultures of rat hepatocytes.
- Author
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Gnoni GV, Geelen MJ, Bijleveld C, Quagliariello E, and van den Bergh SG
- Subjects
- Acetates metabolism, Acetic Acid, Animals, Cells, Cultured, Cholesterol biosynthesis, Cycloheximide pharmacology, Fatty Acids biosynthesis, Hypothyroidism metabolism, Liver drug effects, Male, Rats, Rats, Inbred Strains, Time Factors, Water metabolism, Lipids biosynthesis, Liver metabolism, Triiodothyronine pharmacology
- Abstract
Within 4 h following the addition of 3,3',5 triiodo-L-thyronine to monolayer cultures of hepatocytes isolated from hypothyroid rats, a very distinct stimulation of fatty acid and cholesterol synthesis, measured as incorporation of either [1-14C]acetate or [3H]H2O into these lipid fractions, is observed. A smaller but significant increase in the rate of lipogenesis occurs in hepatocytes derived from euthyroid animals. These stimulatory effects of triiodothyronine are also observed in the presence of cycloheximide, indicating that the described early and direct stimulation of lipogenesis by the thyroid hormone is, at least in part, independent of protein synthesis.
- Published
- 1985
- Full Text
- View/download PDF
42. Carrier mediated GABA translocation into rat brain mitochondria.
- Author
-
Passarella S, Atlante A, Barile M, and Quagliariello E
- Subjects
- Animals, Binding Sites drug effects, Binding, Competitive, Biological Transport, Active, Cytosol metabolism, GABA Plasma Membrane Transport Proteins, In Vitro Techniques, Kinetics, Male, Metals pharmacology, NADP metabolism, Oxidation-Reduction drug effects, Phenanthrolines pharmacology, Phosphates metabolism, Rats, Antiporters, Brain metabolism, Carrier Proteins metabolism, Glutamates metabolism, Mitochondria metabolism, Nerve Tissue Proteins, gamma-Aminobutyric Acid metabolism
- Abstract
GABA added to rat brain mitochondria causes oxidation of intramitochondrial NAD(P)H as well as inducing glutamate efflux from the mitochondrial matrix. The rate of NAD(P)H oxidation shows saturation characteristics, depends on GABA transport across the mitochondrial membrane and is inhibited by non-penetrant compounds and by the metal-complexing agent bathophenanthroline. These results show the existence of a specific GABA carrier. Inhibition studies strongly suggest the existence of two separate binding sites, namely the GABA binding site and the dicarboxylates binding site, as well as suggest the presence of a metal ion (ions) at GABA binding site. The occurrence of a GABA/GLUTAMATE antiport is proposed which allows a cyclical route to account for GABA synthesis and degradation in brain.
- Published
- 1984
- Full Text
- View/download PDF
43. On the binding of brain myelin basic protein to chromatographic resins.
- Author
-
Riccio P, De Santis A, Bobba A, and Quagliariello E
- Subjects
- Animals, Cattle, Chromatography, Gel, Electrophoresis, Polyacrylamide Gel, Structure-Activity Relationship, Brain Chemistry, Myelin Basic Protein metabolism, Resins, Plant metabolism
- Abstract
Myelin basic protein, only in association with certain detergents, is able to bind irreversibly to the usual gel filtration media. While this binding is greatly advantageous in purification of proteolipid (the other major myelin protein), the question arises of the uncommon, nonphysiological behaviour of the basic protein. A relationship between binding property and basic protein structure is suggested.
- Published
- 1985
- Full Text
- View/download PDF
44. Effect of chemical carcinogens and partial hepatectomy on "in vivo" (35S)methionine interaction with rat liver tRNA.
- Author
-
Kanduc D, Aresta A, Rossiello MR, Ranieri T, and Quagliariello E
- Subjects
- Animals, Ethionine pharmacology, Hepatectomy, Liver drug effects, Male, Radioisotope Dilution Technique, Rats, Rats, Inbred Strains, Sulfur Radioisotopes, Dimethylnitrosamine pharmacology, Liver metabolism, Liver Regeneration, Methionine metabolism, Methylnitrosourea pharmacology, RNA, Transfer metabolism
- Abstract
The effect of carcinogens given by a single or multiple injections on the extent of (35S)methionine interaction with hepatic tRNA was studied in normal and partially hepatectomized rats. Either partial hepatectomy or administration of ethionine (100 or 330 mg/kg body weight) and dimethylnitrosamine (120 mg/kg body weight) by multiple i.p. injections inhibited the (35S)methionine-tRNA interaction, while administration of hepatocarcinogenic chemicals plus PH resulted rather in a stimulation. Methylnitrosourea enhanced the extent of interaction when administered in a single dose (100 mg per kg body weight) 18 h after partial hepatectomy.
- Published
- 1989
- Full Text
- View/download PDF
45. "In vivo" (35S)-methionine interaction with rat-liver DNA and the effect of chemical carcinogens.
- Author
-
Kanduc D and Quagliariello E
- Subjects
- Animals, Carcinogens pharmacology, DNA Damage, Liver metabolism, Male, Methionine pharmacokinetics, Rats, Rats, Inbred Strains, Spectrophotometry, Ultraviolet, DNA metabolism, Methionine metabolism
- Abstract
1. After intraperitoneal administration of (35S)methionine (25 mg, 1.6 mCi/kg), detectable amount of radioactivity resulted associated to rat-liver DNA: the interaction reached the maximum value (about 18 pmol/mumol DNA P) by 2 h after administration of radioactive aminoacid. 2. The (35S)-binding was inhibited by the hepatocarcinogenic ethionine and dimethylnitrosamine, and was stimulated by the non-hepatocarcinogenic methylnitrosourea. 3. Hplc analysis of (35S)DNA enzymic digest evidenced two radioactive compounds, the UV behaviour of which is reported.
- Published
- 1988
- Full Text
- View/download PDF
46. Increase in the ADP/ATP exchange in rat liver mitochondria irradiated in vitro by helium-neon laser.
- Author
-
Passarella S, Ostuni A, Atlante A, and Quagliariello E
- Subjects
- Adenosine Diphosphate pharmacology, Animals, Atractyloside pharmacology, Electrochemistry, Glucose metabolism, Glucosephosphate Dehydrogenase metabolism, Hexokinase metabolism, Kinetics, Mitochondria, Liver drug effects, Mitochondria, Liver metabolism, NADP metabolism, Oligomycins pharmacology, Oxidation-Reduction, Phosphorylation, Rats, Spectrophotometry, Adenosine Diphosphate metabolism, Adenosine Triphosphate metabolism, Lasers, Mitochondria, Liver radiation effects
- Abstract
To gain some insight into the mechanism of cell photostimulation by laser light, measurements were made of the rate of ADP/ATP exchange in mitochondria irradiated with the low power continuous wave Helium Neon laser (energy dose 5 Joules/cm2). To do this a method has been developed to continuously monitor ATP efflux from phosphorylating mitochondria caused by externally added ADP, by photometrically following the NADP+ reduction which occurs in the presence of glucose, hexokinase, glucose-6-phosphate dehydrogenase and effluxed ATP. The NADP+ reduction rate shows hyperbolic dependence on ADP concentration (Km and Vmax values 8.5 +/- 0.87 microM and 20.7 +/- 0.49 nmoles NADP+ reduced/min x mg mitochondrial protein, respectively), and proves to measure the activity of the ADP/ATP translocator as shown by inhibition experiments using atracyloside, powerful inhibitor of this carrier. Irradiation was found to enhance the rate of ADP/ATP antiport, with externally added ADP ranging between 5 and 100 microM. As a result of experiments carried out with mitochondria loaded with either ATP or ADP, the increase in the activity of the ADP/ATP translocator is here proposed to depend on the increase in the electrochemical proton gradient which occurs owing to irradiation of mitochondria.
- Published
- 1988
- Full Text
- View/download PDF
47. Lymphocyte-Salmonella interaction: energy dependence and thiol group involvement.
- Author
-
Passarella S, Barile M, Quagliariello E, Caretto G, Cedola MC, and Jirillo E
- Subjects
- Adenosine Triphosphate metabolism, Adhesiveness, Electron Transport drug effects, Energy Metabolism, Humans, In Vitro Techniques, Oligomycins pharmacology, Receptors, Cell Surface metabolism, Sulfhydryl Compounds metabolism, Lymphocytes microbiology, Salmonella physiology
- Abstract
In order to gain better insight into lymphocyte-Salmonella interaction investigation has been carried out on energy-dependence and involvement of thiol groups in this process by using a modified rosette test. Binding frequency, number of bound bacteria/number of binding lymphocytes and the number of bacteria-binding sites/lymphocyte were found to be enhanced by externally added ATP and decreased by both uncouplers and electron transfer chain inhibitors. Treatment of either bacteria or lymphocytes with thiol reagents, such as mersalyl or N-ethyl-maleimide, prevents lymphocyte-Salmonella adherence, thus showing the presence of thiol groups involved in the binding mechanism in both bacteria and cells. Consistently, as a result of mersalyl inhibition, a decrease in the number of bacteria-binding sites/lymphocyte was also found.
- Published
- 1986
- Full Text
- View/download PDF
48. Oxaloacetate uptake into rat brain mitochondria and reconstruction of the malate/oxaloacetate shuttle.
- Author
-
Passarella S, Barile M, Atlante A, and Quagliariello E
- Subjects
- Animals, Biological Transport drug effects, Kinetics, Mersalyl pharmacology, Mitochondria drug effects, Oxidation-Reduction, Rats, Brain metabolism, Malates metabolism, Mitochondria metabolism, Oxaloacetates metabolism
- Abstract
Reconstruction, using non-synaptosomal rat brain mitochondria, has been made here of the malate/oxaloacetate shuttle, made possible by the occurrence in rat brain mitochondria of a carrier mediated transport for oxaloacetate (Km = 60 microM), sensitive to dicarboxylate analogues and mersalyl, and of the two isoenzymes of malate dehydrogenase. Malate/oxaloacetate shuttle shows a high affinity for malate (Km = 100 microM) and Vmax = 40 nmoles NADH oxidized/min X mg mitochondrial protein at 20 degrees C. Its rate appears to depend on the activity of the malate/oxaloacetate exchange across the mitochondrial membrane. A possible role for the oxaloacetate carrier is proposed in aminoacid brain metabolism.
- Published
- 1984
- Full Text
- View/download PDF
49. Uptake of thiamin by isolated rat liver mitochondria.
- Author
-
Barile M, Passarella S, and Quagliariello E
- Subjects
- Animals, Biological Transport, Cell Compartmentation, Cell-Free System, In Vitro Techniques, Mitochondria, Liver ultrastructure, Phosphorylation, Rats, Mitochondria, Liver metabolism, Thiamine metabolism
- Abstract
Investigation is made here of 14C-thiamin uptake by rat liver mitochondria in vitro. Following incubation with mitochondria, 14C-thiamin remained in the mitochondrial pellet in spite of several washings of the organelles. Accordingly, externally added thiamin produced intra/extra-mitochondrial concentration ratios up to 5.4 and 14C-thiamin space/3H2O space ratios higher than one. These ratios decreased with increasing vitamin concentrations, thus suggesting the occurrence of saturation characteristics for vitamin uptake into mitochondria. Thiamin was proven to enter both intermembrane and matrix spaces, where neither binding to intramitochondrial protein nor phosphorylation were found to occur. Moreover thiamin uptake inhibition by both metal ions and certain thiamin analogues was also found.
- Published
- 1986
- Full Text
- View/download PDF
50. Fumarate permeation in rat liver mitochondria: fumarate/malate and fumarate/phosphate translocators.
- Author
-
Atlante A, Passarella S, Giannattasio S, and Quagliariello E
- Subjects
- Animals, Biological Transport, Active, Citric Acid Cycle, Ethylmaleimide metabolism, Kinetics, Malonates metabolism, Mersalyl metabolism, Models, Biological, Rats, Succinates pharmacology, Fumarates metabolism, Malates metabolism, Mitochondria, Liver metabolism, Phosphates metabolism
- Abstract
Fumarate permeation in isolated rat liver mitochondria was demonstrated by measuring malate and phosphate efflux caused by fumarate added externally to the mitochondrial suspension. The existence of two specific fumarate translocators, fumarate/malate and fumarate/phosphate, is shown here. These carriers are distinguished in the light of different kinetic parameters (Km values are 50 microM and 150 microM, and Vmax values are 17 and 40 nmoles/min X mg mitochondrial protein, respectively) and of differing sensitivity to non-penetrant compounds. Fumarate was found to cause oxaloacetate efflux from mitochondria by means of an indirect process which involves the cooperation of both fumarate/malate and malate/oxaloacetate translocators. Results are discussed in the light of the physiological role played by fumarate translocation in both ureogenesis and aminoacid metabolism.
- Published
- 1985
- Full Text
- View/download PDF
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