[111] Branched-chain amino acid aminotransferase (pig heart mitochondria)

摘要: Publisher Summary This chapter presents the assay, purification, and properties of branched-chain amino acid aminotransferase. The α -keto formed is converted to 2, 4 dinitrophenylhydrazone, which selectively extracted with toluene. hydrazone then transferred sodium carbonate solution. method based on Friedemann Haugen's slight modifications. Toluene routinely used, because all hydrazones these branched chain acids can be well by toluene, contamination -ketoglutarate essentially negligible. Considerable activity for transamination found both in supernatant mitochondrial fractions. All purification procedures are carried out at 4°. purified enzyme shown as a single protein electrophoresis an acrylamide-gel plate immunodouble diffusion test ultracentrifugation. Enzyme limited valine, leucine, isoleucine, -ketoglutarate. optimal pH 8.6, enhanced severalfold addition 20 m M 2-mercaptoethanol. Electrophoresis acrylamide gel reveals that moves anode faster than enzyme.