Control of leucine metabolism with special reference to branched-chain amino acid transaminase isozymes.

摘要: Abstract Branched chain amino acid transaminase has three types of isozyme (isozymes I–III) in rat. Isozyme I is found all tissues, whereas isozymes II and III are present only the liver brain, respectively. specific for leucine, while transaminate valine, leucine isoleucine at equal rates. readily inducible by administration glucocorticoid a high protein diet. Hypophysectomy induces mitochondria. Ketone body formation from very active slices kidney lactating mammary gland less slice. Leucine metabolism controlled activity transaminase, this enzyme not rate limiting kidney. Valine or inhibited ketogenesis kidney, but liver. Ketogenesis also oxidative phosphorylation. Thus dinitrophenol inhibits ketone mitochondrial preparations should be fortified with ADP, MgCl2 succinate to achieve maximal reaction rate. Isozymes normal adult rat liver, was fetal Rapidly growing Yoshida hepatomas contained III, no II. Various Morris showed variety patterns, such as normal, combination two types. Cultured hepatocytes, containing I, were transformed chemical carcinogens cells acquired III. There close correlation between appearance deviation chromosomal numbers various strains cultured hepatocytes. These results indicate that change pattern branched-chain regulated genetic expression, mere selection cell population. It suggested good markers determination grade differentiation.