Tyrosine-ol-ketoglutarate transaminase activity in the liver was increased several-fold by the injection of hydrocortisone or L-tyrosine into the rat (1,2). Since the activity of this enzyme was measured with an excess of its coenzyme, pyridoxal-P, it was assumed that the increase in the activity represented an increase in the concentration of the protein moiety of the transaminase. Few enzymes...

An apparent epidemic cluster of toxic liver disease was reexamined among workers exposed to the solvent dimethylformamide. A demographically similar but unexposed group from a preemployment population was used for comparison. Analysis, after data transformation of the liver transaminases, revealed significant differences between the two populations with respect to the serum glutamic pyruvic tra...

The reactions of two analogues of 4-aminobutyrate, namely 4-aminohex-5-ynoate and 4-aminohex-5-enoate, with three transaminases were studied. Three pure enzymes were used, aminobutyrate transaminase (EC 2.6.1.19), ornithine transaminase (EC 2.6.1.13) and aspartate transaminase (EC 2.6.1.1), and the course of the reactions was studied by observing changes in the absorption spectrum of the bound ...

Case 1: Mr F., a 65-year-old man with hypertension and atrial fibrillation, began longterm anticoagulation with warfarin 1 year ago. He presented with a 1-week history of nausea, anorexia, jaundice, and altered mental status. His laboratory workup showed elevated serum transaminases and direct bilirubin. Could warfarin be potentially responsible? Case 2: Mr S., a 75-year-old man with diabetes a...

The regulation of synthesis of the valine-alanine-alpha-aminobutyrate transaminase (transaminase C) was studied in Escherichia coli mutants lacking the branched-chain amino acid transaminase (transaminase B). An investigation was made of two strains, CU2 and CU2002, each carrying the same transaminase B lesion but exhibiting different growth responses on a medium supplemented with branched-chai...

A new protease which specifically acts on the apo-form of pyridoxal enzymes was discovered in rat small intestine and skeletal muscle. This enzyme was puriCed about SM-fold from the small intestine of vitamin Be-deficient rats. Some proporties of the enzyme and its action were studied. The enzyme split the apo-protein of ornithine transaminase into two products, a homogeneous smaller protein an...

The serum levels of the mitochondrial enzymes), aspartate transatninase II, malate dehydrogenase II and glutamate dehydrogenase were studied in 82 cases of acute hepatitis. The activity ratio alanine transaminase/glutamate dehydrogenase and the C/M-ratios of aspartate transaminase and malate dehydrogenase were also studied. The serum levels of the mitochondrial en2ymes glutamate dehydrogenase, ...