Identification of residues responsible for functional specificity in enzymes is a challenging and important problem in protein chemistry. Active-site residues are generally easy to identify, but residues outside the active site are also important to catalysis and their identities and roles are more difficult to determine. We report a method based on analysis of multiple sequence alignments, emb...

1. Homogenates of liver or kidney from rat, mouse, dog and guinea pig formed ornithine from proline but not from glutamate. Rat kidney was most active in this reaction and was used for further studies. 2. The overall reaction was found to be catalysed by proline oxidase to yield glutamic gamma-semialdehyde, followed by transamination of this product with glutamate as catalysed by ornithine-keto...

negative energy balance in pregnant ewes during last two month of gestation could result in fatal pregnancy toxemia and affects ewe and lamb health. the understanding of variations of energy related metabolites during this critical period may cast light upon to a better management of the situation. this study describes the variations of serum energy related biochemical metabolites at a period o...

background: paraquat is a non-selective contact herbicide, widely used to control weeds in agriculture farms and aquatic plants in surface waters. paraquat can have adverse effects on the health of aquatic organisms. the aim of this study was to detect the alterations in the blood biochemical parameters of common carp exposed to sub-lethal concentrations of commercial formulations of paraquat. ...

As relatively little information is available on the properties of aspartate aminotransferase from photosynthetic tissue, isolation and characterization of the two major electrophoretically distinct forms of this enzyme from seedling oat leaf homogenates were undertaken. These two forms are designated I for the more anionic form and II for the less anionic form. Form I, 80 to 90% of the total a...

In a previous publication (1) we have described the synthesis and chemical properties of /3-fluoro-oxaloacetic acid. This acid was found to be a potent inhibitor of mitochondriil malic dehydrogenase (1,2). It is probable that fluoro-oxaloacetate inhibits other enzymes which react with oxaloacetate. We have performed further experiments in order to test this hypothesis. As a part of this study t...

The primary structure of mitochondrial aspartate aminotransferase from chicken is reported. The enzyme is a dimer of identical subunits. Each subunit contains 401 amino acid residues; the calculated subunit molecular weight of the apoform is 44,866. The degree of sequence identity with the homologous cytosolic isoenzyme from chicken is 46%. A comparison of the primary structures of the mitochon...

The pyridoxal phosphate reactivation of the apo form of aspartate aminotransferase (EC 2.6.1.1) in human serum has been studied with "normal" and above-normal activity of this enzyme. The extent of the reactionation did not depend on the presence of the substrates, L-aspartate or 2-oxoglutarate. Reactivation was greatest with 110 mumol of added pyridoxal phsophate present per liter during a pre...

PURPOSE To review the medical literature regarding the histopathologic and biochemical liver test abnormalities in chronic asymptomatic or oligosymptomatic alcoholics. METHODS Review of articles in the MEDLINE and LILACS databases regarding serum levels and prevalence of alterations in aspartate-aminotransferase, alanine-aminotransferase, alkaline phosphatase, and total bilirubin, in relation...