Purification and properties of aromatic amino acid aminotransferases from Azospirillum brasilense UAP 14 strain.

摘要: The purification and characterization of AAT1, one two aromatic amino acid aminotransferase (EC 2.6.1.57) in Azospirillum brasilense, is described. Purified AAT1 had a subunit mass 33 kDa nondenatured molecular 66 kDa, suggesting dimeric structure. Other properties include pI 5.04, an optimum temperature 45 °C, pH 8.5. utilized all acids, the L-tryptophan derivatives such as L-5-methyl tryptophan L-flourtryptophan, L-histidine. apparent Km values for L-tyrosine, L-phenylalanine, were 0.19, 0.43, 1.05 mM, respectively. enzyme was competive inhibited by indole-3-pyruvic with Ki 0.17 mM.Key words: aminotransferase, indole acetic production.