Purification and characterization of a major collagenase from Streptomyces parvulus

Abstract

A major collagenase was purified about 96-fold from a crude enzyme sample of Streptomyces parvulus by chromatography on Q-Sepharose, Sephacryl S-200, and butyl-Toyopearl. The purified enzyme showed a relative molecular mass of approximately 52,000 on SDS-PAGE and a pH optimum at about 9.0, and was strongly inhibited by metal-chelating agents. It also cleaved 4- phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-D-Arg specifically at the Leu-Gly bond, with a Km value of 0.60mM at pH 9.0 at 37°C. Based on the amino acid sequences of the N-terminal region and internal tryptic peptides, the corresponding gene was cloned. The DNA sequence of the cloned gene indicated that the enzyme is produced as an 864-residue precursor protein with a 408-residue prepro sequence followed by a 456-residue mature enzyme moiety. The enzyme is most homologous with the collagenase from S. coelicolor, the identity being 73%, and it is thought to be a member of the Vibrio collagenase subfamily.