抄録
Polymyxin acylase from Pseudomonas sp. M-6-3 can deacylate not only polymyxin antibiotics, but also N-fatty acyl-peptides and N-fatty acyl-amino acids. We found that this enzyme causes intramolecular N2→←N6 acyl transfer in monooctanoyl-L-lysine; when N2-octanoyl-L-lysine is the substrate, N6-octanoyl-L-lysine is produced at pH 10.5, but when N6-octanoyl-L-lysine is the substrate, N2-octanoyl-L-lysine is produced at pH 8.0. In these reactions, the deacylation proceeded gradually at the final stage and eventually, both N2-octanoyl-L-lysine and N6-octanoyl-L-lysine were hydrolyzed to L-lysine and octanoic acid. Furthermore, this enzyme showed intermolecular acyltransferase activity, transferring several N-octanoyl-DL-amino acids to N-octanoyl-hydroxylamine. This acyltransfer ability of polymyxin acylase offers a new method of enzymic N-acylation of compounds containing amino components.
