SIMPLIFIED PROCEDURE FOR MEASURING AMINO-PROCOLLAGEN PEPTIDASE TYPE-I

A new procedure which is simple, rapid, and sensitive has been devised for measuring amino-procollagen peptidase type I extracted from fetal calf skin. The substrate is a form of procollagen (pN-collagen) type I collected from dermatosparactic calf skin labelled by [14C]carboxymethylation of the half-cystine residues located in the aminoterminal extensions. The assay relies on the property of collagen and pN-collagen to precipitate when the reaction mixture is made 27% in ethanol while the excised aminoterminal peptides remain in solution. Kinetic parameters and endopeptidase activity have been determined. © 1979.