Purification and characterization of a novel prolyl aminopeptidase from Maitake (Grifola frondosa)

We have found a novel prolyl aminopeptidase in Grifola frondosa. The enzyme was purified by DEAE-Sepharose CL-6B, Butyl-Toyopearl, Sephacryl S-100, and Mono-Q column chromatographies. The purified enzyme exists as a dimer and gives high activity toward L-proline-p-nitroanilide. The enzyme was strongly inhibited by p-chloromercuribenzoic acid and iodoacetic acid and markedly inhibited by phenylmethylsulfonyl fluoride and arphamenin A.