The hemorrhagin catrocollastatin inhibits collagen-induced platelet aggregation by binding to collagen via its disintegrin-like domain.

Catrocollastatin, a 50 kDa snake venom protein purified from Crotalus atrox, specifically inhibits platelet-collagen adhesion and collagen-induced aggregation. Catrocollastatin is composed of an N-terminal domain, a metalloproteinase domain, a disintegrin-like domain and a cysteine-rich C-terminal domain. The present studies show that catrocollastatin exerts its effect by binding to collagen. Based on the amino acid sequence and homology analysis, a cyclic oligopeptide corresponding to a conservative fragment containing the sequence SECD in the disintegrin-like domain has been synthesized. Like its protein parent, the synthetic peptide inhibits collagen-induced aggregation and possesses the ability to bind to collagen. This is the first snake venom protein with a disintegrin-like structure shown to bind to an integrin ligand matrix molecule instead of an integrin.