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

An oxidase catalyzing conversion of Nα-benzyloxycarbonyl-l-lysine (Nα-Z-l-lysine) to Nα-benzyloxycarbonyl-l-aminoadipate-δ-semialdehyde (Nα-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 ɛ-amino group of Nα-acyl-l-lysine and the α-amino group of Nɛ-acyl-l-lysine. The apparent Km value for Nα-acetyl-l-lysine was much larger than that for Nɛ-acetyl-l-lysine. The peptidyl l-lysines, l-lysine and many other l-amino acids were also oxidized, but Nα-acyl-d-lysine, Nɛ-acyl-d-lysine and d-amino acids were not. Thus, the conversion of Nα-Z-l-lysine into Nα-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.