Isolation and characterization of a dipeptidyl aminopeptidase from Streptomyces sp. WM-23

A screening test was undertaken to isolate microorganisms that produced dipeptidyl aminopeptidase. The hydrolytic activity toward alanyl-phenylalanine p-nitroanilide was found in a culture filtrate of a actinomyces strain (WM-23), newly isolated from a soil sample. The enzyme (WM-23 dipeptidyl aminopeptidase) was isolated from the culture filtrate as a homogeneous preparation. The WM-23 enzyme, inhibited by phenylmethylsulfonyl fluoride, may be classified to mammalian dipeptidyl aminopeptidase II. The enzymatic characteristics were investigated.