Inhibitors of procollagen N-protease. Synthetic peptides with sequences similar to the cleavage site in the pro alpha 1(I) chain.

A series of peptides was synthesized with amino acid sequences identical with the cleavage site at which the procollagen N-protease cleaves the N-terminal propeptide from the pro alpha 1 chain of type I procollagen. Peptides up to 11 residues in length did not serve as substrates for the enzyme, an observation consistent with the demonstration that the N-protease will not cleave denatured procollagen or dissociated pro alpha chains. Several of the peptides, however, served as effective inhibitors of the cleavage of procollagen. Comparison of the inhibitor activities of peptides of varying lengths suggested that the L-phenylalanine found three residues to the left of the cleavage site was important for inhibitor activity. This suggestion was confirmed by synthesis of analogues of inhibitory peptides in which L-phenylalanine was replaced by D-phenylalanine, tyrosine, lysine, aspartic acid, or glycine.