1. Acetylation of aspartate aminotransferase from pig heart inhibits completely the enzymic activity when the coenzyme is in the amino form (pyridoxamine phosphate) or when the coenzyme has been removed, but not when the coenzyme is in the aldehyde form (pyridoxal phosphate). 2. The group the acylation of which is responsible for the inhibition has been identified with the in-amino group of a l...

The present study describes the isolation of a protein from Escherichia coli possessing kynurenine aminotransferase (KAT) activity and its identification as aspartate aminotransferase (AspAT). KAT catalyses the transamination of kynurenine and 3-hydroxykynurenine to kynurenic acid and xanthurenic acid respectively, and the enzyme activity can be easily detected in E. coli cells. Separation of t...

Azide at an effective antimicrobial concentration, 7.7 mmol/liter, inhibits neither the cytoplasmic or the mitochondrial isoenzymes of human aspartate aminotransferase (EC 2.6. 1. 1) or porcine malate dehydrogenase (EC 1.1.1.37). It markedly prolongs the usefulness of substrates in assays for estimating aspartate aminotransferase activity (aspartate substrate without azide deteriorates in less ...

Reportedly, serum manganese concentrations increase after myocardial infarction, closely correlated with increased serum aspartate aminotransferase activity. However, these conclusions are apparently based on analyses of contaminated samples. Serum manganese concentrations after myocardial infarction have been re-investigated by neutron activation analysis, and no significant increase could b...

In two experiments, postpubertal gilts, individually housed in gestation stalls, were fed daily 1.9 kg of a purified diet providing 0.45, 1.5, 2.1 or 83 mg of vitamin B-6/d. The erythrocyte aspartate aminotransferase (more commonly known as glutamic-oxaloacetic transaminase) activity coefficient (EGOT-Ac) of gilts fed the low vitamin B-6 diet (0.45 mg vitamin B-6/d) for 121 d increased 200%, wh...

Thirteen out of 17 patients with fulminant hepatic failure had plasma fibronectin concentrations below the normal range (194--472 micrograms/ml), the mean concentration in all 17 patients being 117.9 +/- SE 19.4 micrograms/ml. There was a significant negative correlation between plasma fibronectin concentration and aspartate aminotransferase activity, suggesting that fibronectin is consumed dur...

Aminotransferases and glutamate dehydrogenase are two main types of enzymes involved in the initial steps of amino acid catabolism, which plays a key role in the cheese flavor development. In the present work, glutamate dehydrogenase and aminotransferase activities were screened in twenty one strains of lactic acid bacteria of dairy interest, either cheese-isolated or commercial starters, inclu...

1. Butan-1-ol solubilizes that portion of rat liver mitochondrial aspartate aminotransferase (EC 2.6.1.1) that cannot be solubilized by ultrasonics and other treatments. 2. A difference in electrophoretic mobilities, chromatographic behaviour and solubility characteristics between the enzymes solubilized by ultrasonic treatment and by butan-1-ol was observed, suggesting the occurrence of two fo...

Pseudomonas aeruginosa possesses dual enzymatic sequences to both L-phenylalanine and L-tyrosine, a biosynthetic arrangement further complicated by the presence of five aromatic aminotransferases. Each aminotransferase is capable of transamination in vitro with any of the three keto acid intermediates in the aromatic pathway (phenylpyruvate, 4-hydroxyphenylpyruvate, or prephenate). The fraction...