PRODUCTION, PURIFICATION, AND PROPERTIES OF SERINE CARBOXYPEPTIDASE FROM PAECILOMYCES-CARNEUS

Seventeen strains of the genus Paecilomyces were examined for their ab ility to produce serine carboxypeptidase. Paecilomyces cameus IFO 7012 exhibited the highest potency for serine carboxypeptidase production. A maximum yield of serine carboxypeptidase was obtained by koji cultu re of the strain at 22 degrees C for 7 days. The serine carboxypeptida se was purified to homogeneity from an extract of the koji culture. Th e molecular weight of the enzyme was estimated to be 47,000 by HPLC. T he isoelectric point of the enzyme was determined to be 4.0, and the o ptimum pH was 4.0 toward benzyloxycarbonyl-L-glutamyl-L-tyrosine (Z-Gl u-Tyr) and enzyloxycarbonyl-L-phenylalanyl-L-alanine (Z-Phe-Ala), resp ectively, The enzyme was strongly inhibited by phenylmethylsulfonyl fl uoride and p-chloromercurybenzoate. Relative hydrolysis rates of N-acy lpeptides and kinetic studies indicated that the enzyme preferred subs trates having bulky amino acids in the penultimate position from their carboxy-termini.