Transaminases of branched chain amino acids. IV. Purification and properties of two enzymes from rat liver.

摘要: Abstract Two transaminases for the branched chain amino acids (valine, leucine and isoleucine) with α-ketoglutarate were isolated from normal rat liver purified by DEAE-cellulose, hydroxylapatite Sephadex column chromatographies. One enzyme (enzyme I) was eluted 0.02 M phosphate buffer a DEAE-cellulose catalyzed transamination of all three acids. The other II) 0.18 specific leucine. Half total activity I found in supernatant, while only one quarter II localized supernatant. rest remained mitochondrial fraction. optimal pH 8.2 that 8.7. K m value 7.5·10 −4 2.5·10 −2 M. Enzyme activated 2-mercaptoethanol but not. Anti-serum against hog heart transaminase, which has similar properties to I, inhibited not II. two enzymes compared their physiological significance discussed.