Production of Aminopeptidase and Carboxypeptidase by Streptomyces peptidofaciens

Abstract

Streptomyces peptidofaciens KY 2389, a new species isolated from a soil sample, exhibited the highest potencies in production of both aminopeptidase and carboxypeptidase among about 1,300 strains tested. Optimum pH values of both aminopeptidase and carboxypeptidase for Leu-β-naphthyl-amide and Cbz-Gly-Leu were 8.0. Aminopeptidase was thermostable and the activity was not lost by treatment at 70°C for 1 hr, in the presence of Ca2+. Carboxypeptidase was heat-labile and over 50% of the activity was lost by treatment at 60°C for 1 hr. Of the synthetic peptides tested, Leu-Gly-Gly and Cbz-Gly-Leu were the most suitable substrates for amino-peptidase and carboxypeptidase, respectively.