Search

The study of the relationship between the activity and stability of enzymes under crowding conditions in the presence of osmolytes is important for understanding the functioning of a living cell. The effect of osmolytes (trehalose and betaine) on the secondary and tertiary structure and activity of muscle glycogen phosphorylase b (Ph b) under crowding conditions created by PEG 2000 and PEG 20000 was investigated using dynamic light scattering, differential scanning calorimetry, circular dichroism spectroscopy, fluorimetry and enzymatic activity assay. At 25 °C PEGs increased Ph b activity, but PEG 20000 to a greater extent. Wherein, PEG 20000 significantly destabilized its tertiary and secondary structure, in contrast to PEG 2000. Trehalose removed the effects of PEGs on Ph b , while betaine significantly reduced the activating effect of PEG 20000 without affecting the action of PEG 2000. Under heat stress at 48 °C, the protective effect of osmolytes under crowding conditions was more pronounced than at room temperature, and the Ph b activity in the presence of osmolytes was higher in these conditions than in diluted solutions. These results provide important insights into the complex mechanism, by which osmolytes affect the structure and activity of Ph b under crowding conditions. • PEG 2000 and especially PEG 20000 destabilized structure of Ph b and increased its enzymatic activity. • Trehalose completely removed destabilizing effects of both PEGs but betaine only partialy • When heated in the presence of osmolytes, Ph b activity under crowding conditions was higher than in dilute solutions. • Protective effect of osmolytes under crowding conditions was most noticeable under heat stress. [ABSTRACT FROM AUTHOR]

Xu and colleagues recently revealed the critical role of Cryptosporidium 's feeder organelle in nutrient uptake, showcasing the parasite's ability to harness glucose and glucose-6-phosphate from host cells. This illuminates the sophisticated energy metabolism and survival strategies of the parasite, highlighting potential therapeutic targets. [ABSTRACT FROM AUTHOR]

Temperature is an important factor that conditions the physiological responses of fish, generating a stressful condition when in non-ideal parameters. Thus, the objective was to evaluate metabolic aspects in the muscle of fish Astyanax lacustris submitted to thermal shock. The specimens were subjected to 2, 6, 12, 24, 48, and 96 h of exposure to 15 °C and 31 1 °C, with their respective controls 23 °C. At 15 °C there was a reduction in glycogenolysis in the initial periods indicated by changes in glycogen phosphorylase (GP), pyruvate and lactate. Subsequently, there was an increase in GP activity, pyruvate levels and hexokinase activity in the next time periods, suggesting an increase in energy demand. At 31 °C there was observed low need for the protein metabolism, indicated by reduction in the activity of aspartate aminotransferase and alanine aminotransferase. At 15 °C, initial periods show an increase in glutathione reductase activity and an increase in carbonylated protein levels, indicating induction of oxidative stress for muscle. At 31 °C, there was a punctual increase in reduced glutathione levels at 24 h. In addition, the integrated biomarker response index proved to be a good ally in the evaluation of a set of biomarkers, corroborating the results observed by the biomarkers individually. Thus, it is possible to conclude that the acute thermal shock affects the metabolism of A. lacustris muscle, which undergoes rearrangements to deal with temperature, where 15 °C is more stressful than 31 °C. [Display omitted] • Glycogenolysis occurs at the initial time (2 h) of thermal shock at 15 °C. • Protein damage at 15 °C suggests muscle oxidative stress in Astyanax lacustris. • Thermal shock affects muscle metabolism with 15 °C more stressful than 31 °C. • IBR index analyses corroborate the individual enzymatic changes of the metabolic pathways. [ABSTRACT FROM AUTHOR]

Considerable evidence confirms the importance of Cyp26a1 to all-trans-retinoic acid (RA) homeostasis during embryogenesis. In contrast, despite its presence in postnatal liver as a potential major RA catabolizing enzyme and its acute sensitivity to induction by RA, some data suggested that Cyp26a1 contributes only marginally to endogenous RA homeostasis postnatally. We report reevaluation of a conditional Cyp26a1 knockdown in the postnatal mouse. The current results show that Cyp26a1 mRNA in WT mouse liver increases 16-fold upon refeeding after a fast, accompanied by an increased rate of RA elimination and a 41% decrease in the RA concentration. In contrast, Cyp26a1 mRNA in the refed homozygotic knockdown reached only 2% of its extent in WT during refeeding, accompanied by a slower rate of RA catabolism and no decrease in liver RA, relative to fasting. Refed homozygous knockdown mice also had decreased Akt1 and 2 phosphorylation and pyruvate dehydrogenase kinase 4 (Pdk4) mRNA and increased glucokinase (Gck) mRNA, glycogen phosphorylase (Pygl) phosphorylation, and serum glucose, relative to WT. Fasted homozygous knockdown mice had increased glucagon/insulin relative to WT. These data indicate that Cyp26a1 participates prominently in moderating the postnatal liver concentration of endogenous RA and contributes essentially to glucoregulatory control. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different nitrogen conditions and phosphorus levels were examined for PCC10605. • The trade-off between glycogen and C-PC production was observed in PCC10605. • N limitation and high P levels trigger mRNA of carbonic anhydrase, glg C and glg P. • Light intensity and CO 2 concentration also influenced the effect of N/P levels. • PCC10605 showed remarkable carbon uptake efficacy of 76% in direct air capture. Cyanobacteria hold promise for simultaneous carbon capture and chemicals production, but the regulation and effect of nitrogen (N) and phosphorus (P) remains unclear. This study investigates major productions of glycogen, protein, and C-phycocyanin (C-PC) in Cyanobacterium aponinum PCC10605 under different N/P levels, alongside changes in light and CO 2. Increasing nitrate (NO 3 –) from 2 to 6 mM resulted in a 9.7-fold increase in C-PC and reduced glycogen to 8.9 %. On the other hand, elevating phosphorus from 0.1 to 2 mM under limited nitrogen enhanced biomass and glycogen through the upregulation of carbonic anhydrase, ADP-glucose pyrophosphorylase, and glycogen phosphorylase. Changes in phosphorus levels and CO 2 inlet concentrations affected metabolites accumulation and carbon capture efficiency, leading to the best condition of 76 % uptake capacity in direct air capture (DAC). All findings underscore the trade-off between glycogen and protein, representing the importance of N/P levels in nutrient modulation of PCC10605. [ABSTRACT FROM AUTHOR]

This research aimed to explore the potential influence of mitochondria on the rate of anaerobic glycolysis. We hypothesized that mitochondria could reduce the rate of anaerobic glycolysis and pH decline by metabolizing a portion of glycolytic pyruvate. We utilized an in vitro model and incorporated CPI-613 and Avidin to inhibit pyruvate dehydrogenase (PDH) and pyruvate carboxylase (PC), respectively. Four treatments were tested: 400 μM CPI-613, 1.5 U/ml Avidin, 400 μM CPI-613 + 1.5 U/ml Avidin, or control. Glycolytic metabolites and pH of the in vitro model were evaluated throughout a 1440-min incubation period. CPI-613-containing treatments, with or without Avidin, decreased pH levels and increased glycogen degradation and lactate accumulation compared to the control and Avidin treatments (P < 0.05), indicating increased glycolytic flux. In a different experiment, two treatments, 400 μM CPI-613 or control, were employed to track the fates of pyruvate using [13C 6 ]glucose. CPI-613 reduced the contribution of glucose carbon to tricarboxylic acid cycle intermediates compared to control (P < 0.05). To test whether the acceleration of acidification in reactions containing CPI-613 was due to an increase in the activity of key enzymes of glycogenolysis and glycolysis, we evaluated the activities of glycogen phosphorylase, phosphofructokinase, and pyruvate kinase in the presence or absence of 400 μM CPI-613. The CPI-613 treatment did not elicit an alteration in the activity of these three enzymes. These findings indicate that inhibiting PDH increases the rate of anaerobic glycolysis and pH decline, suggesting that mitochondria are potential regulators of postmortem metabolism. [ABSTRACT FROM AUTHOR]

The accumulation of rabbit muscle glycogen phosphorylase b (RMGP b) in electrostatic complexes with the cationic polyelectrolyte poly 2-(dimethylamino) ethyl methacrylate in its quenched form (QPDMAEMA) was studied in two buffer solutions. In the N -bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES) buffer, large complexes of RMGPb-QPDMAEMA were formed which adopted smaller sizes as QPDMAEMA concentration increased. However, in N -(2-hydroxyethyl)piperazine- N ′-(2-ethanesulfonic acid) (HEPES) buffer, the hydrodynamic radius of the formed complexes gradually increased as the polymer concentration increased. Zeta potential measurements (ζ p) showed that RMGP b significantly changed the ζ p of the QPDMAEMA aggregates. Fluorescence studies showed that the interaction between RMGP b and QPDMAEAMA was enhanced as polymer concentration increased. Specifically, 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescence indicated that in the BES buffer the aggregates became denser as more QPDMAEMA was added, while in the HEPES buffer the density of the formed structures decreased. RMGP b 's secondary structure was examined by Attenuated Total Reflection - Fourier Transform Infrared (ATR-FTIR) and Circular Dichroism (CD) showing that QPDMAEMA interaction with RMGP b does not induce any changes to the secondary structure of the enzyme. These observations suggest that cationic polyelectrolytes may be utilized for the formulation of RMGP b in multifunctional nanostructures and be further exploited in innovative biotechnology applications and bioinspired materials development. [Display omitted] • RMGP b forms large complexes with the cationic polyelectrolyte QPDMAEMA. • Complexes are studied in two buffer solutions of different ionic strength. • The nanostructures depend on the protein/polymer mixing ratio and ionic strength. • Complexation does not affect the secondary structure of the protein. • The work illustrates an allosteric, dimeric enzyme complex with a polyelectrolyte. [ABSTRACT FROM AUTHOR]

Chemical chaperones are a class of small molecules, which enhance protein stability, folding, inhibit protein aggregation, and are used for long-term storage of therapeutic proteins. The combined action of chemical chaperones trehalose, betaine and lysine on stability, aggregation and oligomeric state of muscle glycogen phosphorylase b (Ph b) has been studied. Dynamic light scattering data indicate that the affinity of trehalose to Ph b increased in the presence of betaine or lysine at both stages (stage of nucleation and aggregate growth) of enzyme aggregation at 48 °C, in contrast, the affinity of betaine to the enzyme in the presence of lysine remained practically unchanged. According to differential scanning calorimetry and analytical ultracentrifugation data, the mixture of trehalose and betaine stabilized Ph b stronger than either of them in total. Moreover, the destabilizing effect of lysine on the enzyme was almost completely compensated by trehalose and only partially by betaine. The main protective effect of the mixtures of osmolytes and lysine is associated with their influence on the dissociation/denaturation stage, which is the rate-limiting one of Ph b aggregation. Thus, a pair of chaperones affects the stability, oligomeric state, and aggregation of Ph b differently than individual chaperones. • The affinity of Tre to Ph b is increased in 1.4–1.7 times in the presence of Bet or Lys at 48 °C. • The affinity of Bet to Ph b in the presence of Lys remains practically unchanged at 48 °C. • Tre and Bet stabilize the Ph b dimer enhancing the protective effect of each other. • The negative effect of Lys on Ph b can be removed by increasing concentration of Tre or Bet. • A mixture of chaperones has a different effect on Ph b than that of individual chaperones. [ABSTRACT FROM AUTHOR]

• Juvenile isolation disrupts PPI by increasing the lactate in PFC of adult rats. • Juvenile isolation increases the lactate in PFC via activating glucose metabolism. • Glycogen phosphorylase inhibition in PFC improves the PPI disrupted by isolation. • Glycogen phosphorylase inhibition in PFC decreases the OXPHOS-related mRNAs. Repeated early environmental deprivation is regarded as a typical paradigm to mimic the behavioral abnormalities and brain dysfunction that occur in psychiatric disorders. Previously, we reported that social isolation could disrupt prepulse inhibition (PPI) in Sprague-Dawley (SD) rats, producing the typical characteristics of a schizophrenia animal model. Based on further analysis of previous proteomic and transcriptomic data, a disrupted balance of glucose metabolism was found in the prefrontal cortex (PFC) of isolated rats. Subsequently, in the first experiment of this study, we investigated the effects of juvenile social isolation (postnatal days (PND) 21–34) on PPI and lactate levels in PND56 rats. Compared with the social rearing group, rats in the isolated rearing group showed disrupted PPI and increased lactate levels in the PFC. In the second experiment, at PND55, the model rats were acutely injected with a glycogen phosphorylase inhibitor (4-dideoxy-1,4-imino-darabinitol, DAB) or control saline in the bilateral PFC. Our data showed that acute DAB administration (50 pmol, 0.5 μl) significantly improved the disrupted PPI and decreased the levels of oxidative phosphorylation (OXPHOS)-related mRNAs as well as lactate. In summary, our results suggested that excess astrocytic lactate production was involved in the impairment of auditory sensory gating of isolated rats, which may contribute to the metabolic pathogenesis of schizophrenia. [ABSTRACT FROM AUTHOR]

• Vanillin attenuated testicular oxidative imbalance in type 2 diabetes. • Vanillin modulated testicular purinergic and cholinergic dysfunctions in type 2 diabetes. • Vanillin restored testicular glucose metabolism in type 2 diabetes. Testicular dysfunctions leading to male infertility has been reported in type 2 diabetes (T2D), with glucose dysmetabolism, cholinergic and purinergic dysfunction being major contributors. In the present study, the effect of vanillin on glucose metabolism, purinergic and cholinergic dysfunctions were investigated in testicular tissues of T2D rats. Male Sprague-Dawley rats were divided into 6 groups containing 5 rats each. T2D was induced in rats by administering 10 % fructose ad libitum for 14 days followed by a single intraperitoneal injection (40 mg/kg body weight) of streptozotocin. T2D rats were orally administered with vanillin at 150 and 300 mg/kg body weight (bw). Diabetic control (DC) consisted of untreated diabetic rats, while normal control (NC) consisted of normal rats and they were administered with distilled water only. Metformin was used as the standard antidiabetic drug. After 5 weeks treatment, the rats were sacrificed, and the testes were harvested. Induction of T2D led to significantly depleted testicular levels of glutathione, glycogen content, superoxide dismutase and catalase enzyme activities, with concomitantly elevated levels of nitric oxide, malondialdehyde, acetylcholinesterase, glucose-6-phosphatase, fructose-1,6-biphophastase, glycogen phosphorylase, amylase and lipase activities. These activities and levels were significantly reversed to near normal in rats treated with both doses of vanillin as compared with metformin. These results, when taken together, suggest the therapeutic effect of vanillin against hyperglycemia-mediated metabolic dysfunctions in testes of T2D rats. This is depicted by the ability of the phenolic to attenuate oxidative imbalance, purinergic and cholinergic dysfunctions, while suppressing glucose dysmetabolism. [ABSTRACT FROM AUTHOR]

Using the previous batch of fermented product to initiate fermentation (i.e. , community-level bioaugmentation) is a common production technique for fermented foods. As the saccharification, fermentation, and aroma-producing agent in strong-flavor Baijiu brewing, medium-temperature Daqu is usually produced by spontaneous fermentation without any exogenous microorganisms inoculated. Here, we selected Daqu from day 12 (FerDq) and day 30 (MatDq) of the previous batch as starters to perform bioaugmentation. Bioaugmentation enhanced total acidity, enzymatic activities, and volatiles, particularly alcohols and pyrazines. Metagenomics revealed that bioaugmentation with 5% or 10% (w/w) FerDq enhanced the relative abundances of Staphylococcus and Bacillus , whereas bioaugmentation with 5% or 10% (w/w) MatDq enriched Bacillus , Aspergillus , Talaromyces , and Rasamsonia. The increase in liquefying activity in MatDq groups was due to the increase in alpha-amylase and glycogen phosphorylase abundances, mainly caused by the enrichment of Aspergillus , Talaromyces , and Bacillus. Bioaugmentation with FerDq significantly increased the gene abundance of carboxyesterase and esterifying activity of Daqu via Staphylococcus and Bacillus. The enriched Bacillus , Staphylococcus , and Paenibacillus in FerDq groups facilitated the production of pyrazines. The metabolic pathway of phenylethyl alcohol biosynthesis varied among different groups. In the control group, it was mainly produced by aryl-alcohol dehydrogenase, which originated from Lactobacillales, while in the bioaugmented groups, it was mainly produced through alcohol dehydrogenase and formaldehyde dehydrogenase, which were derived from Rhizopus and Bacillus in the FerDq groups and from Rasamsonia , Talaromyces , Rhizopus , and Bacillus in the MatDq groups. This study revealed the feasibility of producing enzymatic activity- and aroma-enhanced Daqu through community-level bioaugmentation. [Display omitted] • The impact of community-level bioaugmentation on Daqu production was explored. • Bioaugmentation with fermented Daqu could enrich Staphylococcus and Bacillus. • Bioaugmentation with fermented Daqu raised enzymatic activities and pyrazine content. • Bioaugmentation with mature Daqu could enrich Bacillus and Eurotiales. • Bioaugmentation with mature Daqu raised pyrazine and phenylethyl alcohol content. [ABSTRACT FROM AUTHOR]

Acetamiprid (ACMP) is a second-generation neonicotinoid that has been extensively used in the last few years. The present study examined the toxic effects of ACMP on the pancreas and glucose homeostasis through the evaluation of histological and biochemical changes and the possible ameliorative role of fenugreek seed extract (FG). Fifty adult albino rats were divided into 5 groups: negative control, positive control, FG-treated, ACMP-treated, and ACMP + FG-treated groups by oral gavage for 12 weeks. The ACMP-treated group highlighted significant elevations in plasma glucose, glycosylated haemoglobin levels (HbA1c), serum amylase, and serum lipase, along with a decrease in plasma insulin levels. In addition, significant increases in tumour necrosis factor- alpha (TNF-α) and malondialdehyde (MDA) were associated with reductions in the levels of interleukin 10 (IL-10), glutathione peroxidase, and catalase. Moreover, glucose-6-phosphatase and glycogen phosphorylase were significantly increased, with a significant reduction in hexokinase and liver glycogen stores. These biochemical changes were associated with histological changes in pancreatic sections stained by haematoxylin and eosin, Masson stain, and Orcein stain. ACMP-treated cells showed a marked reduction in β- cell immune reactivity to insulin, with pronounced p53, and beclin 1 immune expression. The use of FG with ACMP induced partial protection except for hexokinase and glycogen phosphorylase. [Display omitted] • Acetamiprid increases glucose hemostasis, glycosylated hemoglobin, and reduces insulin levels. • Acetamiprid increases TNF-α, MDA levels, while reducing IL-10, IL-10, and catalase. • Acetamiprid causes vacuolation of pancreatic cells, decreases p53 and beclin 1 expression, and affects insulin levels. • Fenugreek and Acetamiprid provide partial protection, except for hexokinase and glycogen phosphorylase. [ABSTRACT FROM AUTHOR]

Glycogen is an essential nutritional component of the Pacific abalone (Haliotis discus hannai), and its content is a crucial factor in selecting and breeding high-quality abalone. Glycogen catabolism is facilitated by two key enzymes: glycogen debranching enzyme (GDE) and glycogen phosphorylase (GP). This study aimed to explore the relationship between GDE and GP gene polymorphisms and glycogen content in abalone. To this end, four and two SNP loci located in the exonic regions of these two genes, respectively, were screened and identified in 264 abalone using direct sequencing. The results of genetic polymorphism and correlation analysis revealed a negative correlation between the expression of GDE and GP and glycogen content. Moreover, the study found that the GA haplotype of GDE gene SNP1/3 was significantly associated with high glycogen content, while the TT genotype of GP gene SNP2 was significantly associated with low glycogen content. These results provide molecular markers that could be utilized for selecting and breeding glycogen traits in abalone, indicating the potential influence of GDE and GP polymorphisms on glycogen content. • Glycogen content in 264 samples of H. discus hannai showed a normal distribution. • The expressions of GDE and GP were negatively correlated with glycogen content. • The GA haplotype of SNP1/3 in GDE was strongly associated with high glycogen content. • The TT genotype of SNP2 in GP was strongly associated with low glycogen content. [ABSTRACT FROM AUTHOR]

Cyclic AMP is produced in cells by two different types of adenylyl cyclases: at the plasma membrane by the transmembrane adenylyl cyclases (tmACs, ADCY1~ADCY9) and in the cytosol by the evolutionarily more conserved soluble adenylyl cyclase (sAC, ADCY10). By employing high-resolution extracellular flux analysis in HepG2 cells to study glycogen breakdown in real time, we showed that cAMP regulates glycogen metabolism in opposite directions depending on its location of synthesis within cells and the downstream cAMP effectors. While the canonical tmAC-cAMP-PKA signaling promotes glycogenolysis, we demonstrate here that the non-canonical sAC-cAMP-Epac1 signaling suppresses glycogenolysis. Mechanistically, suppression of sAC-cAMP-Epac1 leads to Ser-15 phosphorylation and thereby activation of the liver-form glycogen phosphorylase to promote glycogenolysis. Our findings highlight the importance of cAMP microdomain organization for distinct metabolic regulation and establish sAC as a novel regulator of glycogen metabolism. [Display omitted] • Soluble adenylyl cyclase (sAC) is a novel regulator of glycogen metabolism. • sAC-cAMP-Epac1 signaling suppresses glycogen breakdown. • sAC-cAMP-Epac1 signaling operates in cells of diverse tissue origins. • cAMP microdomains allow opposite glycogen regulation by sAC and tmACs. [ABSTRACT FROM AUTHOR]

Arginine (Arg) is frequently used in biotechnology and pharmaceutics to stabilize protein preparations. When using charged ions like Arg, it is necessary to take into account their contribution to the increase in ionic strength, in addition to the effect of Arg on particular processes occurring under the conditions of constancy of ionic strength. Here, we examined contribution of ionic strength (0.15 and 0.5 M) to the effects of Arg on denaturation, thermal inactivation and aggregation of skeletal muscle glycogen phosphorylase b (Ph b). Dynamic light scattering, analytical ultracentrifugation, differential scanning calorimetry, circular dichroism and enzymatic activity assay were used to assess the effects of Arg at constant ionic strength compared with the effects of ionic strength alone. We found that high ionic strength did not affect the secondary structure of Ph b , but changed conformation of the protein. Such a destabilization of the enzyme causes an increase in the initial rate of aggregation and inactivation of Ph b thereby affecting its denaturation. Binding of Arg causes additional changes in the protein conformation, weakening the bonds between monomers in the dimer. This causes the dimer to dissociate into monomers, which rapidly aggregate. Thus, Arg acts on these processes much stronger than just ionic strength. • Increasing ionic strength changes Ph b conformation resulting in its destabilization. • High ionic strength increases aggregation and inactivation of Ph b at 48 °C. • Increasing ionic strength has almost no effect on the secondary structure of Ph b. • Effect of Arg is much stronger than just effect of ionic strength on these processes. • Binding of Arg to Ph b results in dimer dissociation to monomers, which aggregate. [ABSTRACT FROM AUTHOR]

• Sodium valproate (VS) stimulates expression of BGP in GSDV animal models. • An open label study of VS in GSDV showed no benefit in people with GSDV. • VS did not stimulate the expression of BGP in people with GSDV. McArdle disease results from a lack of muscle glycogen phosphorylase in skeletal muscle tissue. Regenerating skeletal muscle fibres can express the brain glycogen phosphorylase isoenzyme. Stimulating expression of this enzyme could be a therapeutic strategy. Animal model studies indicate that sodium valproate (VPA) can increase expression of phosphorylase in skeletal muscle affected with McArdle disease. This study was designed to assess whether VPA can modify expression of brain phosphorylase isoenzyme in people with McArdle disease. This phase II, open label, feasibility pilot study to assess efficacy of six months treatment with VPA (20 mg/kg/day) included 16 people with McArdle disease. Primary outcome assessed changes in VO 2 peak during an incremental cycle test. Secondary outcomes included: phosphorylase enzyme expression in post-treatment muscle biopsy, total distance walked in 12 min, plasma lactate change (forearm exercise test) and quality of life (SF36). Safety parameters. 14 participants completed the trial, VPA treatment was well tolerated; weight gain was the most frequently reported drug-related adverse event. There was no clinically meaningful change in any of the primary or secondary outcome measures including: VO 2 peak, 12 min walk test and muscle biopsy to look for a change in the number of phosphorylase positive fibres between baseline and 6 months of treatment. Although this was a small open label feasibility study, it suggests that a larger randomised controlled study of VPA, may not be worthwhile. [ABSTRACT FROM AUTHOR]

• The cDNA of TPS , GYS and GP were cloned from A. gifuensis. • AgTPS was highly expressed before the initiation of diapause. • Expressions of all three genes were inhibited in the maintenance of diapause. • Expression of AgGYS was up-regulated after diapause was terminated. Aphidius gifuensis is an important biological control agent of aphid. It stores sugar as energy reserves before the onset of diapause, a form of dormancy that occurs when environmental conditions become unfavorable for development. In this study, cDNA of three relevant enzymes, trehalose-6-phosphate synthase (TPS), glycogen synthase (GYS) and glycogen phosphorylase (GP) were cloned, and their expression profiles in the preparation and maintenance of diapause, and post-diapause development were analyzed. The results showed that AgTPS, AgGYS and AgGP encoded proteins consisting of 807, 690 and 844 amino acids respectively. The expression profiles of three genes were significantly affected by diapause-inducing condition. The increase of transcription of AgGYS and AgGP were followed by the up-regulate of AgTPS expression in the preparation of diapause, expression of all three genes were inhibited while diapause is maintained, and expression of AgGYS was up-regulated when diapause was terminated. These results suggested that trehalose is accumulated before initiation of diapause and glycogen may play an important role in post-diapause development. [ABSTRACT FROM AUTHOR]

Chemical chaperones are a class of small molecules which enhance folding and prevent aggregation of proteins. Investigation of their effects on the processes of protein aggregation is of importance for further understanding of implication of protein aggregation in neurodegenerative diseases, as well as for solving biotechnological tasks. The effects of chemical chaperones trehalose and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) on the kinetics of aggregation of UV-irradiated muscle glycogen phosphorylase b (UV-Ph b) at 37 °C have been studied. The process of thermal aggregation of UV-Ph b includes a slow stage of structural reorganization of the UV-Ph b molecule, nucleation stage and fast attachment of structurally reorganized UV-Ph b molecules to nuclei formed during the nucleation stage. It was shown that both trehalose and HP-β-CD increased the duration of the nucleation phase and slowed down the rate of structural reorganization of the UV-Ph b molecule. This conclusion has been confirmed by the circular dichroism data. In the absence of chaperones, 82% UV-Ph b aggregates, whereas in the presence of HP-β-CD or trehalose the portion of aggregated protein decreases to 70 and 66%, respectively. The data on analytical ultracentrifugation demonstrated that in the presence of these additives the size of protein aggregates decreased. Analysis of the combined effect of trehalose and HP-β-CD on UV-Ph b aggregation showed that protein aggregation was independently affected by trehalose and HP-β-CD. • Trehalose and 2-hydroxypropyl-β-cyclodextrin are tested as chemical chaperones. • Anti-aggregation activity of chemical chaperones was quantitatively characterized. • UV-irradiated glycogen phosphorylase b (UV-Ph b) was used as a target protein. • Chemical chaperones retard structural reorganization of UV-Ph b. • Extension of nucleation stage was observed in the presence of chemical chaperones. [ABSTRACT FROM AUTHOR]

• A high phosphorylation level is one of the reasons for fast glycolysis. • Protein phosphorylation positively activates three glycolytic enzymes. • Phosphorylation affects postmortem glycolysis through enzyme activity regulation. To verify the effect of protein phosphorylation on glycolysis and elucidate the regulatory mechanism from the perspective of enzyme activity, ovine muscle was treated with a kinase inhibitor, dimethyl sulfoxide, or a phosphatase inhibitor and the activities of glycogen phosphorylase, pyruvate kinase and phosphofructokinase were determined. The protein phosphorylation level was significantly different after incubation of muscle with kinase or phosphatase inhibitors. The pH value and lactate content revealed that a high phosphorylation level was the reason for the fast glycolysis. The glycogen phosphorylase, pyruvate kinase and phosphofructokinase activities were significantly higher in the phosphatase inhibitor group than in the other two groups (p < 0.05). Therefore, protein phosphorylation is involved in activating these three enzymes. In summary, protein phosphorylation plays a role in post-mortem glycolysis through the regulation of enzyme activity in ovine muscle. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of preslaughter shackling on stress, postmortem glycolysis, meat quality, water distribution, and protein structures of pectoralis majors. Before slaughter, Arbor Acres broilers (n = 105, 42 days old, 2.0 to 2.5 kg) were randomly categorized into 3 treatment groups: (I) control group without shackling (NS); (II) 2.5 min shackling (SS); (III) 4.5 min shackling (LS). Each treatment group consisted of 5 replicates with 7 broilers each. Results indicated that preslaughter shackling increased (P < 0.05) plasma corticosterone and adrenocorticotropic hormone concentrations in comparison with the control group. Antemortem shackling increased (P < 0.05) activity of glycogen phosphorylase and phosphofructokinase-1 (PFK-1) accompanying with rapid glycolysis and pH decline at early postmortem. LS treatment led to myosin denaturation, decreased (P < 0.05) α-helix content, and increased (P < 0.05) β-sheet structures proportion in the myofibrillar proteins. Furthermore, meat from LS treatment had higher (P < 0.05) lightness, redness, and poorer water-holding capacity. These results indicated that the longer shackling duration (4.5 min) increased stress and the rate of glycolysis, causing myosin denaturation and changes of the secondary structure in the myofibrillar proteins, which aggravated the deterioration of meat quality. [ABSTRACT FROM AUTHOR]

Glycogen synthase (GS) and glycogen phosphorylase (GP) are two key enzymes in the glycogen synthesis pathway, which catalyze trehalose and glucose transformation in insects. GS and GP can be regulated by trehalose metabolism, which plays an important role in insect growth. However, it is not known whether these genes can be targeted for pest control through regulation of chitin metabolism. We studied the function of Nilaparvata lugens GS and GP (NLGS and NLGP, respectively) using RNA interference, and reported that trehalose and the chitin biosynthesis pathways are regulated by GP and GS, especially TPS3, TRE1-1, and G6PI1, which decreased following knockdown of these two genes. The expression levels of TPS1, TPS2, and several chitin synthesis pathway family genes were significantly increased following dsNlGP injection. Additionally, despite there being no apparent change to the chitin content, an abnormal molting phenotype and wing deformity appeared, and close to 25% insects died. These results demonstrate that silencing of NLGP or NLGS can lead to molting deformities and an elevated mortality rate through the regulation of chitin pathway genes and chitinase genes. NLGP may play a key role in chitin synthesis due to the number of genes regulated, and higher deformity and mortality rates resulting from its knockdown. Unlabelled Image • Suppress the expression of NlGS in Nilaparvata lugens significantly decreased TRE1 enzyme activity at 72 h. • RNAi of NLGP in N. lugens significantly increased the expression of CHS1 , CHS1a , and CHA1b at 48 h. • NLGP or NLGS knockdown in N. lugens can lead to molting deformities and an elevated mortality rate. • Knockdown of NlGP or NlGS in N. lugens influence the trehalose metabolism and chitin metabolism. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is known to be one of the most challenging public health issues of the 21st century. The unwanted side effects associated with conventional synthetic antidiabetic medications have compelled the quest for natural antidiabetic drugs. Therefore, in this study, in vitro, in vivo, and in silico antidiabetic effects of Zingiber capitatum methanol extract (ZcME) were evaluated. ZcME exhibited potent inhibitory activity against α-glucosidase as evidenced by an IC 50 value of 0.45 mg/ml compared to standard voglibose (IC 50 = 0.31 mg/ml). The administration of ZcME at 400 mg/kg significantly (p < 0.05) reduced the fasting blood glucose level compared to the diabetic control group after 20 days of treatment. ZcME decreased blood glucose levels 25.80% on day 1, 45.58% on day 10, and up to 59.17% on day 20 when given at 400 mg/kg BW. Furthermore, GC–MS examination of the plant extracts revealed the presence of sterols, aliphatic acids, aromatics, and esters. In silico study affirm the experimental findings, where the identified compounds showed strong binding affinities against α-glucosidase (7.9 kcal/mol), α-amylase (9.7 kcal/mol), and glycogen phosphorylase enzymes (7.7 kcal/mol), highlighting the antidiabetic potential of ZcME. [ABSTRACT FROM AUTHOR]

• Glycolysis was delayed in meat at the chilling rate of 23.0 °C/h and 25.1 °C/h. • Chilling treatment maintained higher activity of glycolytic enzymes. • Chilling treatment promoted the phosphorylation of glycolytic enzymes. • Chilling treatment inhibited the acetylation of ALDOA, TPI1 and LDH. • Chilling treatment may delay rigor by phosphorylation and acetylation. The aim of this study was to investigate the effects of chilling rate on phosphorylation and acetylation levels of the glycolytic enzymes in meat, including glycogen phosphorylase, phosphofructokinase, aldolase (ALDOA), triose-phosphate isomerase (TPI1), phosphoglycerate kinase, lactate dehydrogenase (LDH). The samples were assigned into three groups: Control, Chilling 1 and Chilling 2, corresponding to the chilling rates of 4.8 °C/h, 23.0 °C/h and 25.1 °C/h respectively. The contents of glycogen and ATP were significantly higher in samples from the chilling groups. The activity and phosphorylation level of the six enzymes were higher in samples at the chilling rate of 25.1 °C/h, while the acetylation level of ALDOA, TPI1 and LDH were inhibited. In brief, glycolysis was delayed and the activity of glycolytic enzymes were maintained at higher level by the changes of phosphorylation and acetylation levels at the chilling rates of 23.0 °C/h and 25.1 °C/h, which may partly explain why very fast chilling improves meat quality. [ABSTRACT FROM AUTHOR]

Aspergillus flavus (A. flavus) infects the peanut seeds during pre-and post-harvest stages, causing seed quality destruction for humans and livestock consumption. Even though many resistant varieties were developed, the molecular mechanism of defense interactions of peanut against A. flavus still needs further investigation. Hence, an interologous host-pathogen protein interaction (HPPI) network was constructed to understand the subcellular level interaction mechanism between peanut and A. flavus. Out of the top 10 hub proteins of both organisms, protein phosphatase 2C and cyclic nucleotide-binding/kinase domain-containing protein and different ribosomal proteins were identified as candidate proteins involved in defense. Functional annotation and subcellular localization based characterization of HPPI identified protein SGT1 homolog, calmodulin and Rac-like GTP-binding proteins to be involved in defense response against fungus. The relevance of HPPI in infectious conditions was assessed using two transcriptome data which identified the interplay of host kinase class R proteins, bHLH TFs and cell wall related proteins to impart resistance against pathogen infection. Further, the pathogenicity analysis identified glycogen phosphorylase and molecular chaperone and allergen Mod-E/Hsp90/Hsp1 as potential pathogen targets to enhance the host defense mechanism. Hence, the computationally predicted host-pathogen PPI network could provide valuable support for molecular biology experiments to understand the host-pathogen interaction. Protein-protein interactions execute significant cellular interactions in an organism and are influenced majorly by stress conditions. Here we reported the host-pathogen protein-protein interaction between peanut and A. flavus, and a detailed network analysis based on function, subcellular localization, gene co-expression, and pathogenicity was performed. The network analysis identified key proteins such as host kinase class R proteins, calmodulin, SGT1 homolog, Rac-like GTP-binding proteins bHLH TFs and cell wall related to impart resistance against pathogen infection. We observed the interplay of defense related proteins and cell wall related proteins predominantly, which could be subjected to further studies. The network analysis described in this study could be applied to understand other host-pathogen systems generally. [Display omitted] • Host-pathogen protein-protein interaction network of A. hypogaea and A. flavus was constructed using interologous method. • Functional annotation and co-expression studies on the PPI network helped to understand the host defense mechanisms. • The interplay of R proteins, TFs, PR proteins and CAZymes were observed and could impart resistance against A. flavus. [ABSTRACT FROM AUTHOR]

Glycogen phosphorylase (GP) is the rate-determining enzyme in the glycogenolysis pathway. Glioblastoma (GBM) is amongst the most aggressive cancers of the central nervous system. The role of GP and glycogen metabolism in the context of cancer cell metabolic reprogramming is recognised, so that GP inhibitors may have potential treatment benefits. Here, baicalein (5,6,7-trihydroxyflavone) is studied as a GP inhibitor, and for its effects on glycogenolysis and GBM at the cellular level. The compound is revealed as a potent GP inhibitor against human brain GPa (K i = 32.54 μM), human liver GPa (K i = 8.77 μM) and rabbit muscle GPb (K i = 5.66 μM) isoforms. It is also an effective inhibitor of glycogenolysis (IC 50 = 119.6 μM), measured in HepG2 cells. Most significantly, baicalein demonstrated anti-cancer potential through concentration- and time-dependent decrease in cell viability for three GBM cell-lines (U-251 MG, U-87 MG, T98-G) with IC 50 values of ∼20–55 μM (48- and 72-h). Its effectiveness against T98-G suggests potential against GBM with resistance to temozolomide (the first-line therapy) due to a positive O6-methylguanine-DNA methyltransferase (MGMT) status. The solved X-ray structure of rabbit muscle GP–baicalein complex will facilitate structure-based design of GP inhibitors. Further exploration of baicalein and other GP inhibitors with different isoform specificities against GBM is suggested. • Baicalein revealed as a potent inhibitor of all three glycogen phosphorylase (GP) isforms: liver, muscle and brain. • Its binding at GP was predicted using docking and validated using X-ray crystallography. • The compound binds at the GP inhibitor site, intercalated between Phe285 and Tyr613. • Baicalein revealed as an effective inhibitor of glycogenolysis (IC50 = 119.6 μM), measured in HepG2 cells. • It demonstrated promising anti-cancer potential against three glioblastoma cell-lines. [ABSTRACT FROM AUTHOR]

Neural substrates for estrogen regulation of glucose homeostasis remain unclear. Female rat dorsal vagal complex (DVC) A2 noradrenergic neurons are estrogen- and metabolic-sensitive. The ventromedial hypothalamic nucleus (VMN) is a key component of the brain network that governs counter-regulatory responses to insulin-induced hypoglycemia (IIH). Here, the selective estrogen receptor-alpha (ERα) or -beta (ERβ) antagonists MPP and PHTPP were administered separately to the caudal fourth ventricle to address the premise that these hindbrain ER variants exert distinctive control of VMN reactivity to IIH in the female sex. Data show that ERα governs hypoglycemic patterns of VMN astrocyte glycogen metabolic enzyme, e.g. glycogen synthase and phosphorylase protein expression, whereas ERβ mediates local glycogen breakdown. DVC ERs also regulate VMN neurotransmitter signaling of energy sufficiency [γ-aminobutyric acid] or deficiency [nitric oxide, steroidogenic factor-1] during IIH. Neither hindbrain ER mediates IIH-associated diminution of VMN norepinephrine (NE) content. Both ERs oppose hypoglycemic hyperglucagonemia, while ERβ contributes to reduced corticosterone output. Outcomes reveal that input from the female hindbrain to the VMN is critical for energy reserve mobilization, metabolic transmitter signaling, and counter-regulatory hormone secretion during hypoglycemia, and that ERs control those cues. Evidence that VMN NE content is not controlled by hindbrain ERα or -β implies that these receptors may regulate VMN function via NE-independent mechanisms, or alternatively, that other neurotransmitter signals to the VMN may control local substrate receptivity to NE. • Estrogen receptor-alpha (ERα) or -beta (ERβ) antagonist was injected icv to hypoglycemic female rat hindbrain (HB). • HB ERα governs ventromedial hypothalamic nucleus (VMN) glycogen enzyme protein levels; ERβ controls VMN glycogen mass. • HB ERs regulate VMN transmitters that signal metabolic stability, e.g. γ-aminobutyric acid and nitric oxide. • Hypoglycemic diminution of VMN norepinephrine content is HB ER-independent. • HB ERα and -β oppose hypoglycemic hyperglucagonemia, while ERβ suppresses corticosterone output. [ABSTRACT FROM AUTHOR]

Recently, the dissemination of antibiotic resistance genes (ARGs) via plasmid-mediated conjugation has been reported to be facilitated by a series of contaminants. This has highlighted potential challenges to the effective control of this principal mode of horizontal transfer. In the present study, we found that low levels (<0.02 mgN/L) of free nitrous acid (FNA) remarkably inhibited (over 90%) the conjugative transfer of plasmid RP4, a model broad-host-range plasmid, between Escherichia coli. The antimicrobial role of FNA at the applied dosages was firstly ruled out, since no dramatic reductions in viabilities of donor or recipient were observed. Instead, FNA appeared to reduce the available intracellular free Mg2+, which was confirmed to be triggered by the liberation of intracellular Fe2+. These alterations in intracellular Mg2+ and Fe2+ concentrations were found to significantly limit the available energy for conjugative transfer through suppression of glycolysis by decreasing the activities of glycogen phosphorylase and glyceraldehyde-3-phosphate dehydrogenase and also by diverting the glycolytic flux into the pentose phosphate pathway via activation of glucose-6-phosphate dehydrogenase towards the generation of NADPH rather than ATP. Moreover, RP4-encoding genes responsible for DNA transfer and replication (traI , traJ and trfAp), coupling (traG) and mating pair formation (traF and trbBp) were all significantly down-regulated after FNA treatment, indicating that the transfer apparatus required for plasmid processing and delivery was deactivated. By validating the inhibitory effects of FNA on conjugation in real wastewater, this study highlights a promising method for controlling the dissemination of ARGs in systems such as wastewater treatment plants. Image 1 • FNA effectively inhibited RP4-mediated conjugative transfer by over 90%. • FAN resulted in the decrease of intracellular Mg2+ but the increase of intracellular Fe2+. • FNA limited energy supply by suppressing glycolysis and activating pentose phosphate pathway. • FNA disabled the transfer apparatus encoded by RP4. • The feasibility of FNA in conjugation inhibition was confirmed in real wastewater. [ABSTRACT FROM AUTHOR]

Authors: Frances Conti-Ramsden MBBS Academic Clinical Fellow1, Carolyn Gill PhD BRC Research Assistant1, Paul T Seed MSc CStat Senior Lecturer in Medical Statistics1, Kate Bramham PhD Clinical Senior Lecturer in Nephrology2, Lucy C Chappell PhD NIHR Research Professor in Obstetrics1, Fergus P McCarthy PhD Clinical Senior Lecturer in Obstetrics and Gynaecology1,3.Objectives: To determine whether glycogen phosphorylase isoenzyme B (GPBB) and/or brain natriuretic peptide (BNP) concentrations are elevated in pre-eclampsia and superimposed pre-eclampsia (SPE), demonstrating cardiac ischaemia and strain.Study Design: A nested case-control study was performed using samples and clinical data available from a prospective pregnancy cohort. Four groups were selected: healthy pregnant controls (n = 21), pre-eclampsia (n = 19), pre-existing chronic hypertension (CHT) and/or chronic kidney disease (CKD) without (n = 20) or with superimposed pre-eclampsia (SPE) (n = 19). Plasma samples were taken at time of disease or the third trimester in controls.Main Outcome Measures: Plasma concentrations of GPBB and BNP.Results: There was no significant difference in GPBB plasma concentrations between controls and pre-eclampsia (geometric mean (GM) [95% CI]: 4.74 [2.54-8.84]ng/mL vs 5.01 [2.58-9.74]ng/mL, p = 0.90)), or between CHT and/or CKD and SPE (GM [95% CI]: 9.49 [4.93-18.25]ng/mL vs 10.24 [5.27-19.92]ng/mL, p = 0.87). BNP plasma concentrations were significantly raised in women with pre-eclampsia compared to controls (GM [95% CI]: 31.83 [20.18-50.22]pg/mL vs 11.33 [7.34-17.51]pg/mL, p = 0.001). Women with CKD, but not CHT, who developed SPE had elevated BNP concentrations. There were no significant differences in BNP concentration between women with comorbidity (CHT and/or CKD) and controls.Conclusions: GPBB has a limited role as a biomarker in hypertensive disorders of pregnancy. BNP concentrations were elevated in pre-eclampsia compared to controls. This suggests cardiac strain at the time of pre-eclampsia. Further studies are needed to examine whether BNP can identify women at increased risk of cardiovascular disease. [ABSTRACT FROM AUTHOR]

Abstract Muscle-to-meat-transition is influenced by alterations of the energy metabolism. Porcine Musculus triceps brachii (MT) consisted of more fast-twitch-glycolytic muscle fibers and samples, collected 0, 10 and 20 min after slaughter (p.m.), showed higher mitochondrial respiratory activities and ATP concentrations than Musculus longissimus thoracis (LT) samples. Enzyme activities in MT were higher at 0 min (glycogen phosphorylase (GP)), 10 min (GP, citrate synthase (CS)) and at 20 min p.m. (CS). However, LT results were higher at 0 min (lactate dehydrogenase (LDH)), 10 min (phosphofructokinase (PFK), LDH) and at 20 min p.m. (PFK, F 0 F 1 -ATPase (F 0 F 1)). Between 0 min and 10 min p.m. CS activities decreased in LT and MT samples, PFK increased in LT and GP in MT samples. Between 10 min and 20 min p.m. PFK and LDH decreased in LT and GP in MT samples, whereas F 0 F 1 increased in LT and CS in MT samples. The data indicate that muscles with different mitochondria contents show clearly different energy metabolism characteristics. [ABSTRACT FROM AUTHOR]

Vertebrate freeze tolerance requires multiple adaptations underpinned by specialized biochemistry. Freezing of extracellular water leads to intracellular dehydration as pure water is incorporated into growing ice crystals and also results in the cessation of blood supply to tissues, creating an anoxic cellular environment. Hence, the freeze tolerant wood frog, Rana sylvatica , must endure both dehydration and anoxia stresses in addition to freezing. The metabolic responses to freezing, dehydration and anoxia involve both protein/enzyme adaptations and the production of metabolites with metabolic or osmotic functions, particularly glucose and urea. The present study uses a phosphoproteome analysis to examine the differential phosphorylation of metabolic enzymes involved in the production of these two metabolites in liver in response to freezing, anoxia, or dehydration exposures. Our results show stress-specific responses in the abundance of phosphopeptides retrieved from nine glycolytic enzymes and three urea cycle enzymes in liver of wood frogs exposed to 24 h freezing, 24 h anoxia, or dehydration to 40% of total body water loss, as compared with 5 °C acclimated controls. Data show changes in the abundance of phosphopeptides belonging to glycogen phosphorylase (GP) and phosphofructokinase 2 (PFK2) that were consistent with differential phosphorylation control of glycogenolysis and a metabolic block at PFK1 that can facilitate glucose synthesis as the cryoprotectant during freezing. Anoxia-exposed animals showed similar changes in GP phosphorylation but no changes to PFK2; changes that would facilitate mobilization of glycogen as a fermentative fuel for anaerobic glycolysis. Urea is commonly produced as a compatible osmolyte in response to amphibian dehydration. Selected urea cycle enzymes showed small changes in phosphopeptide abundance in response to dehydration, but during freezing differential phosphorylation occurred that may facilitate this ATP expensive process when energy resources are sparse. These results add to the growing body of literature demonstrating the importance and efficiency of reversible protein phosphorylation as a regulatory mechanism allowing animals to rapidly respond to environmental stress. Unlabelled Image [ABSTRACT FROM AUTHOR]

Abstract This study analyzed the effect of gender on the abundances of 20 protein biomarkers of tenderness and/or intramuscular fat content in five muscles: Longissimus thoracis , previously identified as biomarkers of tenderness and/or intramuscular Semimembranosus , Rectus abdominis , Triceps brachii and Semitendinosus , from cows and steers of the Protected Designation Origin Maine Anjou. The protein abundances were quantified using Reverse Phase Protein Array with specific validated antibodies. Among the 20 studied proteins, the abundance of 8 biomarkers involved in energetic metabolism, contraction and cellular stress, was different according to gender. The gender effect was different depending on the muscle type with greater abundances in Semitendinosus , Rectus abdominis and Longissimus thoracis muscles. On the basis of animal characteristics and rearing factors, three rearing practices classes were identified for cows. Among the factors, fattening duration modified the abundance of 12 proteins mainly in Triceps brachii muscle. A positive correlation between the abundance of the small HSP20 and slaughter age was observed in the 5 muscles. Two proteins, Four and a half LIM domains 1 (FHL1) and Glycogen phosphorylase (PYGB) appeared to be muscle, gender and rearing practices independent. These results constitute valuable data to understand how to manage beef quality by controlling these different factors. Significance This study is the first to compare the relative abundance of 20 proteins previously identified as biomarkers of tenderness and/or intramuscular fat (IMF) content of beef meat between cows and steers among 5 different muscles. Its originality is in the use of Reverse Phase Protein Array for fast quantification of the proteins and the integration of data from rearing factors, carcass characteristics and biomarkers of meat qualities. The findings provide evidence for modulating biomarker levels by controlling the choice of animal type and rearing factors according to the type of muscle that would produce animals with the desired meat qualities. Graphical abstract Unlabelled Image Highlights • Relative abundance of 8 protein biomarkers among 20 was different between cows and steers. • HSP20 abundance differed between cows and steers in a muscle-dependent manner. • Gender has very little effect on the abundance of Triceps brachii protein biomarkers. • The muscle type effect on the abundance of biomarkers is greater than gender effect. • FHL1 and PYGB are not affected by gender and rearing practices irrespective of muscle. [ABSTRACT FROM AUTHOR]

Glycogen phosphorylase enzymes (GP) catalyse reversible reactions; the glucose transfer from glycogen to inorganic phosphate (P i , phosphorolysis) or the reverse glucose transfer from glucose-1-phosphate (G-1-P) to glycogen (synthesis). Rabbit muscle GPb (rmGPb) was used as a model enzyme to study the reversible enzyme reaction. To follow both directions of this reversible reaction, we have developed a novel isothermal titration calorimetry (ITC) method for the determination of the direct reaction rate. The preference of forward or reverse reaction was ensured by the 0.1 or 10 concentration ratios of G-1-P/P i , respectively. Substrate specificity was studied using different maltooligosaccharides and glycogen. Based on the K M values, glycogen and 2-chloro-4-nitrophenyl maltoheptaoside (CNP-G7) were found to be analogous substrates, which allowed to optimize the method by taking advantage of the CNP chromophore being detectable in HPLC. In case of CNP-G7, substrate inhibition was observed and characterised by K i of 23 ± 7 mM. Inhibition of human GP is a promising strategy for the treatment of diabetes. Our ITC measurements have confirmed that caffeine and glucopyranosylidene-spiro-thiohydantoin (GTH), as known GPb inhibitors, inhibit the rmGPb-catalysed reversible reaction in both directions. K i values obtained in the direction of synthesis (1.92 ± 0.14 mM for caffeine and 11.5 ± 2.0 μM for GTH) have been shown to be in good agreement with the K i values obtained in the direction of phosphorolysis (4.05 ± 0.26 mM for caffeine and 13.8 ± 1.6 μM for GTH). The higher difference between the inhibition constants of caffeine was explained by the non-competitive mechanism. The described ITC method using the developed experimental design and reaction conditions is suitable for activity measurements of different phosphorylase enzymes on various substrates and is applicable for inhibition studies as well. Image 1 • Reversible enzyme reaction was studied in both directions by ITC. • Substrate specificity of glycogen phosphorylase were determined. • Substrate inhibition was observed on the chromophore containing maltoheptaoside. • Inhibition of forward and reverse reactions resulted in similar inhibition constants. [ABSTRACT FROM AUTHOR]

We recently uncovered a regulatory pathway of the muscle isoform of glycogen phosphorylase (PYGM) that plays an important role in regulating immune function in T cells. Here, using various enzymatic, pulldown, and immunoprecipitation assays, we describe signaling cross-talk between the small GTPases RAS and RAP1A, member of RAS oncogene family (RAP1) in human Kit 225 lymphoid cells, which, in turn, is regulated by the epidermal growth factor receptor (EGFR). We found that this communication bridge is essential for glycogen phosphorylase (PYG) activation through the canonical pathway because this enzyme is inactive in the absence of adenylyl cyclase type 6 (ADCY6). PYG activation required stimulation of both exchange protein directly activated by cAMP 2 (EPAC2) and RAP1 via RAS and ADCY6 phosphorylation, with the latter being mediated by Raf-1 proto-oncogene, Ser/Thr kinase (RAF1). Consistent with this model, PYG activation was EGFR-dependent and may be initiated by the constitutively active form of RAS. Consequently, PYG activation in Kit 225 T cells could be blocked with specific inhibitors of RAS, EPAC, RAP1, RAF1, ADCY6, and cAMP-dependent protein kinase. Our results establish a new paradigm for the mechanism of PYG activation, which depends on the type of receptor involved. [ABSTRACT FROM AUTHOR]

Abstract The early detection of acute myocardial infarction (AMI) upon the onset of chest pain symptoms is crucial for patient survival. However, this detection is challenging, particularly without a persistent elevation of ST-segment reflected in an electrocardiogram or in blood tests. A majority of the available point-of-care testing devices allow accurate and rapid diagnosis of AMI. However, AMI diagnosis is reliable only at intermediate and later stages, with myocardial injury (> 6 h) and MI, based on the expression of specific cardiac biomarkers including troponin I or T (cTnI or cTnT), creatine kinase-MB (CK−MB), and myoglobin. Diagnosis at the early myocardial ischemia stage is not possible. To overcome this limitation, a sensitive and rapid microfluidic paper-based device (µPAD) was developed for the simultaneous detection of multiple cardiac biomarkers for the early and late diagnosis of AMI. The glycogen phosphorylase isoenzyme BB (GPBB) was detected during early (within first 4 h) ischemic myocardial injury. On the same µPAD platform, detection of prolonged elevation of levels of cTnT and CK-MB, which are only produced 6 h after the onset of chest pain in human serum, was possible. Sandwich immunoassay performed on the µPAD achieved reproducibility (RSD approximately 10% and intra-and inter-day precision (CV 10–20%, 99th percentile), as well as consistently stable test results for 28 days, with strong correlation (r2 = 0.962), using the standard Siemens Centaur XPT Immunoassay system. The present findings indicate the potential of the µPAD platform as a point-of-care device for the early diagnosis and prognosis of AMI. Graphical abstract fx1 Highlights • The first POC device developed for early diagnosis and prognosis of AMI. • Wax printed µPAD allows rapid multiplex detection of GPBB, CK-MB and cTnT. • Developed µPAD has potential use in clinical testing. • Results obtained are well correlated with Siemens Centaur XPT Immunoassay system. [ABSTRACT FROM AUTHOR]

Abstract Annulated C -β- d -glucopyranosyl heterocycles were synthesized and tested as inhibitors of glycogen phosphorylase. 2-(β- d -Glucopyranosyl)-1 H -imidazo[4,5- b ]pyridine was formed by ring-closure of O -perbenzoylated C -β- d -glucopyranosyl formic acid with 2,3-diaminopyridine in the presence of triphenylphosphite. Cyclisations of bromomethyl 2,3,4,6-tetra- O -benzoyl-β- d -glucopyranosyl ketone with a set of 2-aminoheterocycles resulted in constitutionally reversed C -β- d -glucopyranosyl imidazoles fused by pyridine, pyrimidine, thiazole, 1,3,4-thiadiazole, benzothiazole and benzimidazole. O -Debenzoylation of the above compounds was effected by standard transesterification to get the test compounds. The 1 H -imidazo[4,5- b ]pyridine proved to be a low micromolar inhibitor (K i = 21.1 μM) of rabbit muscle glycogen phosphorylase b, while the other heterocycles displayed weak or no inhibition against the same enzyme. Graphical abstract Image 1 Highlights • Syntheses of annulated C -β- d -glucopyranosyl imidazoles. • New micromolar inhibitor of glycogen phosphorylase. • Strong effect of the heterocycle on the inhibitory activity. [ABSTRACT FROM AUTHOR]

Abstract Diabetes mellitus is characterized by hyperglycaemia that results from defects in insulin secretion or insulin action and is accompanied by general disturbances metabolism. Psidium guajava (PG) leaf is known to have antidiabetic effects that include lowering of blood glucose. The aim of the study was to investigate the effect of PG leaf extract on tissue activity of glycogen synthase (GS) and glycogen phosphorylase (GP); tissue activity of hormone sensitive lipase (HSL); serum lipid profile; and serum enzyme biomarkers of tissue damage. Diabetes was induced in male Sprague-Dawley rats with a single dose of 40 mg/kg body weight streptozotocin. The aqueous extract of PG leaves was used to treat both normal and diabetic animals (400 mg/kg body weight) for 2 weeks while control animals were treated with the vehicle. At the end of the treatment period, blood, liver and adipose tissue samples were collected from the euthanized animals. The results show that PG extract significantly decreased (P < 0.05) HSL activity in adipose tissue and liver of diabetic animals which was accompanied by increased glycogen levels, reduced serum triglycerides, total cholesterol, LDL-cholesterol and increased HDL-cholesterol. This study demonstrates that P. guajava has significant anti-diabetic effects that include increased glycogen storage and reduced HSL activity in the liver and adipose tissue with an improved serum lipid profile. [ABSTRACT FROM AUTHOR]

Glycogen, as an intracellular deposit of polysaccharide, takes important roles in energy balance of many animals. In fish, however, the role of glycogen during development is poorly understood. In the present study, we assessed changes in glycogen concentration and gene expression patterns of glycogen-metabolizing enzymes in developing masu salmon ( Oncorhynchus masou masou ), a salmonid species inhabiting west side of North Pacific Ocean. As we measured glycogen levels in the bodies and yolk sacs containing the liver separately, the glycogen concentration increased in both parts as the fish developed, whereas it transiently decreased in the yolk sac after hatching, implying glycogen synthesis and breakdown in these tissues. Immunofluorescence staining using anti-glycogen monoclonal antibody revealed localization of glycogen in the liver, muscle and yolk syncytial layer of the pre-hatching embryos and hatched larvae. In order to estimate glycogen metabolism in the fish, the genes encoding homologs of glycogen synthase ( gys1 and gys2 ) and glycogen phosphorylase ( pygma , pygmb and pygl ) were cloned, and their expression patterns were assessed by quantitative PCR and in situ hybridization. In the fish, gys1 and gys2 were robustly expressed in the muscle and liver, respectively. Also, expression of pyg isoforms was found in muscle, liver and yolk syncytial layer during hatching. With changes in glycogen concentration and expression patterns of relevant genes, our results suggest, for the first time, possible involvement of glycogen in energy balance of fish embryos, especially during hatching. [ABSTRACT FROM AUTHOR]

In this work the effect of ionic strength and arginine on the kinetics of aggregation of UV-irradiated muscle glycogen phosphorylase b (UV-Ph b ) was studied using dynamic light scattering at 37 °C at various ionic strengths (0.02–0.7 M). Under these conditions the rate-limiting stage of the overall aggregation process is the structural reorganization of UV-Ph b , which can be characterized by the first order rate constant k I . It was shown that an increase in NaCl concentration caused a decrease in the k I value, suggesting a slowdown of the UV-Ph b structural reorganization. Circular dichroism data confirmed this conclusion. Arginine is widely used in biotechnology as an agent suppressing protein aggregation. However, arginine is a charged molecule, and, when studying the action of arginine on protein aggregation, the effects of ionic strength should be taken into account. To evaluate the effect of arginine, experiments were conducted at fixed values of ionic strength (0.15 M and 0.5 M). It was shown that at a low ionic strength arginine (0–0.13 M) accelerated the process of protein aggregation, whereas at higher ionic strength arginine (0–0.48 M) acted as an aggregation suppressor. [ABSTRACT FROM AUTHOR]

As a primary source of reactive nitrogen species, nitric oxide (NO) is a signaling molecule playing multiple roles in physiological processes. NO exerts these pleiotropic effects mainly through the covalent attachment to the sulfhydryl group of protein cysteines to form S -nitrosothiol (protein S -nitrosylation). It has been two decades since NO was first investigated for its role in meat tenderization. Progress has been made, including studies by manipulating the NO levels in muscle cells, suggesting possible effects in the pre-slaughter and post-slaughter environment. NO has potential effects on the meat quality of beef, lamb, chicken and pork muscles. However, it has been difficult to determine the exact mechanism(s) of NO action as it has variable effects on meat quality including tenderness, water holding capacity and color. It is speculated that NO and protein S -nitrosylation may be involved in muscle to meat conversion through the regulation of postmortem biochemical pathways including glycolysis, Ca 2+ release, proteolysis and apoptosis. [ABSTRACT FROM AUTHOR]

Transcriptomic studies are facilitating the search for the molecular bases of adaptation in natural populations, but the impact of these differences in mRNA content on animal physiology are often unknown. One way to determine if molecular changes have the potential to influence animal physiology and performance is to test for correlated changes at higher levels of biological organization, including enzyme activity. Here, we measure the activities of carbohydrate metabolism enzymes to test if previously documented genetic and transcriptomic variation between ‘dwarf’ and ‘normal’ Lake Whitefish ecotypes are associated with corresponding changes in enzyme activity (measured as maximal rate, V max ) in liver and skeletal muscle. We use laboratory-reared fish from the same populations as prior transcriptomic studies and find that white muscle mRNA content is a good predictor of glycolytic and glycogen metabolism enzyme activity, and dwarf whitefish have evolved higher activities than normal whitefish. However, the differences in hepatic mRNA content found between ecotypes in prior studies are not associated with comparable changes in enzyme activity. For example, dwarf whitefish have lower enzyme activities, but higher transcript abundances for two glycolytic enzymes compared to normal whitefish. Overall, we find that transcriptomic studies successfully highlight evolutionary variation in enzyme activities, but not always in the direction predicted, indicating that a variety of tissue-specific regulatory mechanisms contributed to the evolution of energy metabolism in Lake Whitefish. [ABSTRACT FROM AUTHOR]

High pressure processing (HPP) of pre- rigor longissimus thoracis (strip loin) from prime and bull animals substantially decreased the shear force and improved consumer eating attributes of the final meat product. The improved tenderness in both prime and bull meat was associated with a lower myofibrillar fragmentation index and reduced calpain 1 activity which indicated the mechanism of tenderisation was different from that which occurred in chill aged meat. Light microscopy showed disruption to the fibre packing within the muscle and electron microscopy confirmed significant disruption of the Z discs and M lines and disappearance of the A lines. Thus, HPP is associated with a reduction in the structural integrity and strength of the sarcomeres. These effects were consistent in strip loins sourced from prime and bull stock. HPP also led to the movement of glycogen phosphorylase from the sarcoplasmic fraction to the insoluble myofibrillar fraction in all animals and this was associated with a higher pH at 24 h. [ABSTRACT FROM AUTHOR]

Brain Type Glycogen Phosphorylase (PYGB) has been revealed to participate in the progression of multiple human cancers. Nevertheless, the clinical significance and biological function of PYGB in pancreatic ductal adenocarcinoma (PAAD) remains unclarified. This study first analyzed the expression pattern, diagnostic value, and prognostic significance of PYGB in PAAD using the TCGA database. Subsequently, western blot assessed the protein expression of genes in PAAD cells. The viability, apoptosis, migration, and invasion of PAAD cells were assessed by CCK-8, TUNEL, and Transwell assays. Finally, in vivo experiment evaluated the effect of PYGB on PAAD tumor growth and metastasis. Through our investigation, it was revealed that PYGB had extremely high expression in PAAD and predicted a worse prognosis in patients with PAAD. Besides, the aggressiveness of PAAD cells could be suppressed or enhanced by depleting or supplementing PYGB. In addition, we demonstrated that METTL3 enhanced the translation of PYGB mRNA in an m6A-YTHDF1-dependent manner. Moreover, PYGB was revealed to regulate the malignant behaviors of PAAD cells by the mediation of the NF-κB signaling. Finally, PYGB depletion suppressed the growth and distant metastasis of PAAD in vivo. To conclude, our results indicated that METTL3-mediated m6A modification of PYGB exerted the tumor-promotive effect on PAAD through NF-κB signaling, suggesting PYGB is a potential therapeutic target in PAAD. [ABSTRACT FROM AUTHOR]

We applied raw human liver microsome lysate to a holey carbon grid and used cryo-electron microscopy (cryo-EM) to define its composition. From this sample we identified and simultaneously determined high-resolution structural information for ten unique human liver enzymes involved in diverse cellular processes. Notably, we determined the structure of the endoplasmic bifunctional protein H6PD, where the N- and C-terminal domains independently possess glucose-6-phosphate dehydrogenase and 6-phosphogluconolactonase enzymatic activity, respectively. We also obtained the structure of heterodimeric human GANAB, an ER glycoprotein quality-control machinery that contains a catalytic α subunit and a noncatalytic β subunit. In addition, we observed a decameric peroxidase, PRDX4, which directly contacts a disulfide isomerase-related protein, ERp46. Structural data suggest that several glycosylations, bound endogenous compounds, and ions associate with these human liver enzymes. These results highlight the importance of cryo-EM in facilitating the elucidation of human organ proteomics at the atomic level. [Display omitted] • Using cryo-EM to define the composition of a raw human liver lysate • Simultaneously identifying and solving structures of ten enzymes or complexes • Noting the potential of studying high-resolution structural-omics of human enzymes Su et al. use cryo-electron microscopy to simultaneously identify and solve structures of ten different enzymes or complexes from a raw human liver lysate. Their work highlights the potential of this methodology in facilitating structural-omics of a biological system at the atomic level. [ABSTRACT FROM AUTHOR]

Background Glycogenin-interacting protein 1 (GNIP1) is a tripartite motif (TRIM) protein with E3 ubiquitin ligase activity that interacts with glycogenin. These data suggest that GNIP1 could play a major role in the control of glycogen metabolism. However, direct evidence based on functional analysis remains to be obtained. Objectives The aim of this study was 1) to define the expression pattern of glycogenin-interacting protein/Tripartite motif containing protein 7 (GNIP/TRIM7) isoforms in humans, 2) to test their ubiquitin E3 ligase activity, and 3) to analyze the functional effects of GNIP1 on muscle glucose/glycogen metabolism both in human cultured cells and in vivo in mice. Results We show that GNIP1 was the most abundant GNIP/TRIM7 isoform in human skeletal muscle, whereas in cardiac muscle only TRIM7 was expressed. GNIP1 and TRIM7 had autoubiquitination activity in vitro and were localized in the Golgi apparatus and cytosol respectively in LHCN-M2 myoblasts. GNIP1 overexpression increased glucose uptake in LHCN-M2 myotubes. Overexpression of GNIP1 in mouse muscle in vivo increased glycogen content, glycogen synthase (GS) activity and phospho-GSK-3α/β (Ser21/9) and phospho-Akt (Ser473) content, whereas decreased GS phosphorylation in Ser640. These modifications led to decreased blood glucose levels, lactate levels and body weight, without changing whole-body insulin or glucose tolerance in mouse. Conclusion GNIP1 is an ubiquitin ligase with a markedly glycogenic effect in skeletal muscle. [ABSTRACT FROM AUTHOR]

In this study, molecular interactions of the ligands, quercetin, gallic acid, and metformin with various diabetes mellitus-related protein targets, such as glycogen phosphorylase and peroxisome proliferator-activated receptor gamma, were assessed. It was revealed that quercetin possesses good binding affinity to both targets. Quercetin is a major constituent of methanolic extracts of Phyllanthus emblica fruit. The antihyperglycemic effect of quercetin in streptozotocin (STZ)-induced diabetic rats was examined. The isolated quercetin administered at a dose of 75 mg/kg body weight produced a maximum decrease of 14.78% in blood glucose levels in the diabetic rats after 7 days of treatment. Furthermore, quercetin doses of 50 and 75 mg/kg were shown to significantly improve the profiles of triglycerides, high-density lipoprotein, very-low-density lipoprotein, low-density lipoprotein, and total cholesterol at the end of the study in STZ-induced diabetic rats. The administration of quercetin (25, 50, and 75 mg/kg body weight) daily for 28 days in STZ-induced diabetic rats resulted in a significant decrease in blood glucose and urine sugar levels, with a considerable rise in plasma insulin and hemoglobin levels. Therefore, quercetin is a potential drug with antidiabetic and antihyperglycemic action mediated by changes in the levels of glucose, cholesterol, and triglycerides as indicated by in silico and in vivo studies. [ABSTRACT FROM AUTHOR]

3-(β- d -Glucopyranosyl)-5-substituted-1,2,4-triazoles have been revealed as an effective scaffold for the development of potent glycogen phosphorylase (GP) inhibitors but with the potency very sensitive to the nature of the alkyl/aryl 5-substituent (Kun et al., Eur. J. Med. Chem. 2014, 76, 567). For a training set of these ligands, quantum mechanics-polarized ligand docking (QM-PLD) demonstrated good potential to identify larger differences in potencies (predictive index PI = 0.82) and potent inhibitors with K i 's < 10 μM (AU-ROC = 0.86). Accordingly, in silico screening of 2335 new analogues exploiting the ZINC docking database was performed and nine predicted candidates selected for synthesis. The compounds were prepared in O -perbenzoylated forms by either ring transformation of 5-β- d -glucopyranosyl tetrazole by N -benzyl-arenecarboximidoyl chlorides, ring closure of C -(β- d -glucopyranosyl)formamidrazone with aroyl chlorides, or that of N -(β- d -glucopyranosylcarbonyl)arenethiocarboxamides by hydrazine, followed by deprotections. Kinetics experiments against rabbit muscle GPb (rmGPb) and human liver GPa (hlGPa) revealed five compounds as potent low μM inhibitors with three of these on the submicromolar range for rmGPa. X-ray crystallographic analysis sourced the potency to a combination of favorable interactions from the 1,2,4-triazole and suitable aryl substituents in the GP catalytic site. The compounds also revealed promising calculated pharmacokinetic profiles. [ABSTRACT FROM AUTHOR]

Background Tumor microenvironment is composed of a largely altered extracellular matrix with different cell types. The complex interplay between macrophages and tumor cells through several soluble factors and signaling is an important factor in breast cancer progression. Methods We have extended our earlier studies on monocyte and macrophage conditioned medium (MϕCM) and have carried out proteomic analysis to identify its constituents as well as validation. The 8-gene signature identified through macrophage-breast cancer cell interactions was queried in cBioportal for bioinformatic analyses. Results Proteomic analysis (MALDI-TOF and LC-MS/MS) revealed integrin and matrix metalloproteinases in MϕCM which activated TGF-β1, IL-6, TGF- βRII and EGFR as well as its downstream STAT and SMAD signaling in breast cancer cells. Neutralization of pro-inflammatory cytokines (TNF-α. Il-1β, IL-6) abrogated the MϕCM induced migration but invasion to lesser extent. The 8- gene signature identified by macrophage-tumor interactions (TNF-α, IL-1β, IL-6, MMP1, MMP9, TGF-β1, TGF-βRII, EGFR) significantly co-occurred with TP53 mutation, WTAPP1 deletion and SLC12A5 amplification along with differential expression of PSAT1 and ESR1 at the mRNA level and TPD52and PRKCD at the protein level in TCGA (cBioportal). Together these genes form a novel 15 gene signature which is altered in 63.6% of TCGA (1105 samples) data and was associated with high risk and poor survival ( p < 0.05) in many breast cancer datasets (SurvExpress). Conclusions These results highlight the importance of macrophage signaling in breast cancer and the prognostic role of the15-gene signature. General significance Our study may facilitate novel prognostic markers based on tumor-macrophage interaction. [ABSTRACT FROM AUTHOR]

To characterize the initial stages of protein aggregation, the kinetics of aggregation of UV-irradiated glycogen phosphorylase b (UV-Ph b ) was studied under conditions when the aggregation proceeded at a low rate (10 °C, 0.03 M Hepes buffer, pH 6.8, containing 0.1 M NaCl). Aggregation of UV-Ph b was induced by polyethylene glycol and Ficoll-70, acting as crowders, or a natural osmolyte trimethylamine N-oxide (TMAO). It has been shown that the initial rate of the stage of aggregate growth is proportional to the protein concentration squared, suggesting that the order of aggregation with respect to the protein is equal to two. It has been concluded that the aggregation mechanism of UV-Ph b at 10 °C in the presence of crowders includes the nucleation stage and stages of protein aggregate growth (the basic aggregation pathway). The aggregation mechanism is complicated in the presence of TMAO, and the stage of aggregate-aggregate assembly induced by TMAO should be added to the basic aggregation pathway. It has been shown that the ability of TMAO at a low concentration (0.05 M) to induce aggregation of UV-Ph b is due to the decrease in the absolute value of zeta potential of the protein in the presence of TMAO. [ABSTRACT FROM AUTHOR]

Several physiological functions in fish are shaped by environmental stimuli received during early life. In particular, early-life hypoxia has been reported to have long-lasting effects on fish metabolism, with potential consequences for fish life history traits. In the present study, we examine whether the synergistic stressors hypoxia (40% and 100% air saturation) and temperature (15° and 20 °C), encountered during early life, could condition later metabolic response in European sea bass ( Dicentrarchus labrax ) juveniles. Growth rate and metabolic parameters related to carbohydrate and lipid metabolism in the liver were investigated at the juvenile stage under normoxic and chronic hypoxic conditions. Juvenile growth rates were significantly lower ( p < 1 × 10 − 6 ) under hypoxic conditions and were not improved by prior early-life exposure to hypoxia. Growth was 1.3 times higher ( p < 5 × 10 − 3 ) in juveniles reared at 15 °C during the larval stage than those reared at 20 °C, suggesting that compensatory growth had occurred. Early-life exposure to hypoxia induced higher ( p < 2 × 10 − 6 ) glycogen stores in juveniles even though there was no apparent regulation of their carbohydrate metabolism. In the liver of juveniles exposed to chronic hypoxia, lower glycogen content combined with stimulation of phosphoenolpyruvate carboxykinase gene expression and higher lactate concentration indicated a stimulation of the anaerobic glycolytic pathway. Furthermore, hypoxia only induced lower ( p < 1 × 10 − 3 ) lipid content in the liver of juveniles that had experienced 15 °C at the larval stage. The present study provides evidence that environmental conditions experienced during early life shape the metabolic traits of D. labrax with potential consequences for juvenile physiological performance. [ABSTRACT FROM AUTHOR]

Phosphorylated proteins in ovine muscle induced by salt curing were well investigated. Ten topside muscles of crossbred sheep were ground, mixed and divided into two groups, which were cured for 16 h with 0% and 3% NaCl, respectively. Muscle proteins of two cured groups were analyzed by two-dimensional electrophoresis coupled with Pro-Q Diamond and SYPRO Ruby staining. The differential phosphorylated proteins were determined using LC-MS/MS and the UniProt database. Ten different phosphoproteins (> 1.5 fold) induced by salting were identified, including triosephosphate isomerase, glycogen phosphorylase, creatine kinase M-type, myoglobin, troponin T fast skeletal muscle type, actin, myosin light chain 1/3, tropomyosin beta chain, etc. Most of the different phosphoproteins were involved in glycometabolism, protein function and protein degradation. It is conclusively that salting may influence meat quality through protein phosphorylation, which regulates glycolysis metabolism, protein function and degradation. [ABSTRACT FROM AUTHOR]