Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.1 (aspartate aminotransferase)
 21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The levels of several enzymes have been studied during sporulation of Saccharomyces cerevisia. The specific activities of ribonuclease and aminopeptidase I raised several-fold after transfer of the cells to sporulation medium, whereas the specific activities of phosphofructokinase, glucose-6-phosphate dehydrogenase, tryptophan synthase and pyruvate decarboxylase were not significantly altered. The specific activities of NAD-dependent glutamate dehydrogenase, isocitrate lyase, malate dehydrogenase and fructose bisphosphatase all decreased from the onset of sporulation. The inactivation of these latter enzymes was inhibited by cycloheximide and by inhibitors of energy metabolism. Hexokinase, alcohol dehydrogenase and glutamate oxaloacetate transaminase were partially lost from the cells during the period of ascus maturation. None of the enzyme changes observed proved to be 'sporulation-specific' in that it occurred exclusively in sporulating diploid yeast cells. Therefore it is postulated that the meiotic events and the metabolic changes required for ascospore formation are under separate genetic control in this organism. During sporulation, the cellular content of cytochromes b, c, and aa3 was reduced to 20% or less of that present in vegetative derepressed cells. Since the relative percentage of total to cycloheximide-insensitive mitochondrial protein synthesis was not significantly altered throughout sporulation, and the pattern of mitochondrially synthesized polypeptides was rather similar both in vegetative and in sporulating cells, it appeared that not only degradation but also synthesis and therefore turnover of the mitochondrially coded polypeptides of cytochromes b and aa3 took place during sporulation. The activity ratio of cytochrome c oxidase to F1-ATPase in submitochondrial particles isolated from vegetative cells and from purified asci was almost identical. This indicates that the loss of membrane-bound mitochondrial cytochromes during sporulation is probably due to a nonselective degradation of inner mitochondrial membrane proteins.
 ...
PMID:Protein degradation during yeast sporulation. Enzyme and cytochrome patterns. 18 44

The data of studies in the monoaminoxidase, nuclease and transaminase activity in fractions of mitochondria and nuclei of the human fetus brain in the process of the fetus development evidence for the changes in the activity depending on the morphological and functional maturation of the organ during the antenatal ontogenesis. The monoaminoxidase activity increases by the time of birth. By the 40th week of development the activity of glutamic-aspartic transaminase increases as well. The activity of glutamic-alanine transaminase changes insignificantly. A considerable decrease in the activity of DNase and RNase in the mentioned fractions is observed by the time of the fetus birth. The maximal activity of these enzymes is observed in the first half of the fetus intrauterine development.
 ...
PMID:[Formation of some enzymic systems in the human fetal brain during development]. 66 28

The hydroxyl groups of poly(ethyleneglycol) have been esterified (partly) with a number of carboxylic acids. When these esters are included in dextranpoly(ethyleneglycol)-water biphasic systems the partitions of proteins and membranes between the two phases (and the interface) are in some cases strongly affected. The affinity of serum albumin for the poly(ethyleneglycol)-rich phase is strongly increased when the fatty acid group consists of more than 10 carbon atoms. The partition also depends on the number of double bonds in the fatty acid. A corresponding relationship is found for membranes from spinach chloroplasts. The partitions of ovalbumin, lysozyme (EC 3.2.1.17) and ribonuclease (EC 3.1.4.22) are not influenced by the fatty acid esters. Esters of dibasic carboxylic acids show a minute but marked effect on the partition of proteins in general while malate and tartrate esters affect strongly the partition of chloroplast membranes. The partitions of both proteins and membranes are influenced by poly(ethyleneglycol) deoxycholate. Experiments with malate dehydrogenase (EC 1.1.1.37), lactate dehydrogenase (EC 1.1.1.27), fumarase (EC 4.2.1.2), enolase (EC 4.2.1.11) and glutamate-ocaloacetate transaminase (EC 2.6.1.1) show that their partitions, measured on enzymic activity basis, is changed when esters of benzoic, linolenic, tartaric or deoxycholic acid are included in the biphasic system. The mechanism behind the effect of the esterified poly (ethyleneglycol) on the partition of biomaterial, in this type of aqueous biphasic systems, is discussed in terms of a direct binding of the esters to the partitioned material.
 ...
PMID:The effect of poly(ethyleneglycol) esters on the partition of proteins and fragmented membranes in aqueous biphasic systems. 99 68

Barnase, the extracellular ribonuclease of Bacillus amyloliquefaciens, is shown to undergo a reversible two-state conformational transition at 0.65 mM sodium dodecyl sulfate (SDS) AAT 37 DEGREES. The prinicipal evidence is based on the equivalence of two independent values of the SDS-barnase binding ratio; about 14 mol of SDS/mol of barnase. Both were derived from fluorometric titration data, one being based on simple conservation of SDS and the other on the use of Wyman's theory of linked functions. No SDS is bound to barnase at SDS concentrations below the transition region.
 ...
PMID:A two-state conformational transition of the extracellular ribonuclease of Bacillus amyloliquefaciens (barnase) induced by sodium dodecyl sulfate. 113 66

Lysosomal degradation of intracellular proteins during serum withdrawal is stimulated by a member of the 70-kDa heat shock protein (hsp70) family (Chiang, H.-L., Terlecky, S. R., Plant, C. P., and Dice, J. F. (1989) Science 246, 382-385). This hsp70, isolated by affinity chromatography with RNase S-peptide-Sepharose, is referred to as the 73-kDa peptide recognition protein (prp73). We now report that prp73 binds to several proteins and peptides whose degradative rates are increased during serum withdrawal. prp73 also binds to the pentapeptide, KFERQ, and more weakly to most modified RNase S-peptide derivatives with a single amino acid substitution within the KFERQ sequence. Taken together, these results suggest that prp73 binds to a variety of proteins at peptide regions biochemically related to KFERQ. Three lines of evidence indicate that prp73 is the heat shock cognate protein of 73 kDa (hsc73): (a) among five hsp70s tested, hsc73 binds to RNase S-peptide most avidly, (b) both prp73 and hsc73 also bind to RNase A and aspartate aminotransferase but not to ovalbumin, lysozyme, or ubiquitin, and (c) both prp73 and hsc73 promote uptake and degradation of [3H] RNase S-peptide by lysosomes in vitro, while three other hsp70s are without activity in this assay.
 ...
PMID:Protein and peptide binding and stimulation of in vitro lysosomal proteolysis by the 73-kDa heat shock cognate protein. 157 55

Administration of carbon tetrachloride to normal rats increased activities of hepatic 5(1)-nucleotidase, acid phosphatase, acid ribonuclease while the activities of succinate dehydrogenase, glucose 6-phosphatase, superoxide dismutase and cytochrome P450 were decreased. Levels of lipid peroxides, total lipids and cholesterol of liver were also increased. The activities of serum glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and alkaline phosphatase were increased. Other serum parameters showing changes after carbon tetrachloride were: bilirubin, proteins, cholesterol, triglycerides and lipoprotein-X. Picroliv (from the plant Picrorhiza kurroa) in doses of 6 and 12 mg/kg provided a significant protection against most of the biochemical alterations produced by carbon tetrachloride. The degree of protection afforded by picroliv, when administered simultaneously or as a pretreatment was almost equal.
 ...
PMID:Hepatoprotective activity of picroliv against carbon tetrachloride-induced liver damage in rats. 240 41

Immunochemical techniques with enzymes as the antigen have grown in frequency during the last few years. These techniques have allowed evaluation of enzymes in the presence of endogenous inhibitors. Among those enzymes measured by immunochemical techniques and which have found diagnostic application, mention will be made of alkaline phosphatase (with particular reference to the intestinal, placental, and Regan isoenzymes), lactate dehydrogenase (in which renewed interest has developed due to techniques for specifically measuring the LD-1 isoenzyme), aspartate aminotransferase (of which the cytosolic and mitochondrial forms can now be independently measured by immunochemical techniques), acid phosphatase (for which a specific immunochemical assay for the prostatic enzyme has been widely introduced in diagnostic laboratories), and creatine kinase (for which a variety of immunochemical techniques to measure the M- and B-subunits are now part of standard laboratory assays). Other enzymes which will be discussed in this review include phosphohexose isomerase, amylase, ribonuclease, and lysozyme (muramidase). Finally, the use of enzymes, particularly asparaginase, in the chemotherapy of cancer will be outlined.
 ...
PMID:Immunoassay of enzymes--an overview. 634 26

The activities of alanine aminotransferase (ES 2.6.1.2), aspartate aminotransferase (EC 2.6.1.1) and monoaminoxidase (EC 1.4.3.4) in the liver nuclei and mitochondria of human fes rises gradually beginning from the early periods of the antenatal development till birth and reaches the highest value in the last month of the fetus intra-uterine life. The monoaminoxidase activity is found in the liver nuclei of 21-32-week human feti. The activity of RNase (EC 2.7.7.16) and DNase (EC 3.1.4.5) in the liver nuclei is 10 and 15 times as low, respectively, by the 40th week of development, and 1.5 times as low in mitochondria.
 ...
PMID:[Comparative characteristics of the activity of enzyme systems for nitrogen metabolism in the liver of human fetuses during embryogenesis]. 713 1

The effect of carrot extract on carbon tetrachloride (CCl4)-induced acute liver damage was evaluated. The increased serum enzyme levels (viz., glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, lactate dehydrogenase, alkaline phosphatase, sorbitol and glutamate dehydrogenase) by CCl4-induction were significantly lowered due to pretreatment with the extract. The extract also decreased the elevated serum bilirubin and urea content due to CCl4 administration. Increased activities of hepatic 5'-nucleotidase, acid phosphatase, acid ribonuclease and decreased levels of succinic dehydrogenase, glucose-6-phosphatase and cytochrome P-450 produced by CCl4 were reversed by the extract in a dose-responsive way. Results of this study revealed that carrot could afford a significant protective action in the alleviation of CCl4-induced hepatocellular injury.
 ...
PMID:Hepatoprotective activity of carrot (Daucus carota L.) against carbon tetrachloride intoxication in mouse liver. 750 Jun 38

During L. donovani infection in golden hamsters, tremendous hepatic damage was observed as apparent from increased activities of glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, succinate dehydrogenase, glucose-6-phosphatase and acid ribonuclease. The levels of cytochrome P-450 and related monooxygenases, viz. aniline hydroxylase and aminopyrine-N-demethylase registered significant decrease in infected animals. Sodium stibogluconate, a standard antileishmanial drug, though caused the removal of parasites from infected tissues, but did not help in the recovery of deranged hepatic markers. The results explain the higher mortality of stibanate treated infected animals as compared to untreated animals infected with L. donovani.
 ...
PMID:Effect of sodium stibogluconate on hepatic mixed function oxidase system and marker enzymes of golden hamsters during Leishmania donovani infection. 931 42


1 2 Next >>