The role of coenzyme in determining intracellular contnet of pyridoxal enzymes was assessed by analyzing effects of pyridoxine deficiency on the rapidly degraded, readily dissociable tyrosine aminotransferase (EC 2.6.1.5) and the slowly degraded, nondissociable alanine aminotransferase (EC 2.6.1.2) of rat liver. Synthesis of the tyrosine enzyme was reduced, leading to a decreased amount of this...

A root tip cDNA library, constructed in the lambda Zap II expression vector, was immunoscreened with a monoclonal antibody raised against aspartate aminotransferase-P1 from Lupinus angustifolius L. var Uniharvest. One 1452-base pair clone was isolated. The encoded protein sequence had high homology to both plant and animal aspartate aminotransferase sequences. The clone was converted to the pha...

The activities of the amino acid-catabolizing enzymes, serine dehydratase (EC 4.2.1.16), ornithine aminotransferase (EC 2.6.1.13), tyrosine aminotransferase (EC 2.6.1.5), and alanine aminotransferase (EC 2.6.1.12), were measured in the livers of rats bearing the Morris 7800 hepatoma for varying periods. A relatively rapid decrease in the activities of hepatic serine dehydratase and orni thine a...

Plant peroxisomal glyoxylate aminotransferases play central roles within the photorespiratory pathway. Genes encoding glyoxylate aminotransferases have been isolated from several animals and microbes, but only recently have plant homologs been identified. Three Arabidopsis homologs of alanine (Ala):glyoxylate aminotransferase 2 (AGT2) contain a putative type 1 peroxisomal targeting signal (PTS1...

We investigated the enzyme activity of the blank in the spectrophotometric determination of the aminotransferase activities and aspartate aminotransferase activity. 6 lactate dehydrogenase and 3 malate dehydrogenase preparations from different manufactures and from different organs showed additional and contaminating activity. The additional activity depends upon the 2-oxoglutarate concentratio...

1. Partially purified preparations of rat brain 4-aminobutyrate aminotransferase were inhibited in a time-dependent manner by ethanolamine O-sulphate. The inhibition was not reversed by dialysis. 2. The inhibitor formed an initial reversible complex with the enzyme (K(i)=4.4x10(-4)m) and the rate of inactivation followed pseudo-first-order kinetics (k=7.15x10(-4)s(-1)). The inclusion of 4-amino...