Characterization of Nα-benzyloxycarbonyl-l-lysine oxidizing enzyme from Rhodococcus sp. AIU Z-35-1

Abstract

An oxidase catalyzing conversion of N(alpha)-benzyloxycarbonyl-L-lysine (N(alpha)-Z-L-lysine) to N(alpha)-benzyloxycarbonyl-L-aminoadipate-delta-semialdehyde (N(alpha)-Z-L-AASA) was purified from Rhodococcus sp. AIU Z-35-1, and its properties were revealed. This enzyme catalyzed an oxidative deamination of the epsilon-amino group of N(alpha)-acyl-L-lysine and the alpha-amino group of N(epsilon)-acyl-L-lysine. The apparent K(m) value for N(alpha)-acetyl-L-lysine was much larger than that for N(epsilon)-acetyl-L-lysine. The peptidyl L-lysines, L-lysine and many other L-amino acids were also oxidized, but N(alpha)-acyl-D-lysine, N(epsilon)-acyl-D-lysine and D-amino acids were not. Thus, the conversion of N(alpha)-Z-L-lysine into N(alpha)-Z-L-AASA was catalyzed by the L-amino acid oxidase with broad substrate specificity. This enzyme, a flavoprotein with a molecular mass of 100 kDa, consisted of two identical subunits of 51 kDa.