IDENTIFICATION OF NOVEL HEPARIN-BINDING DOMAINS OF VITRONECTIN

Vitronectin is a multifunctional serum protein which provides a unique regulatory link between cell adhesion, humoral defense mechanism and the hemostatic system, and the heparin-binding properties of vitronect in are thought to have participated in various functional aspects, In addition to the carboxy-terminal glycosaminoglycan-binding motif, we r eport on two novel heparin-binding domains which were identified using phage display technique, One heparin-binding domain is located betwee n amino acids Asp(82) and Cys(137) at the end of the connector region, while the other is in the second hemopexin-type repeat, between amino acids Lys(175) and Asp(219) of the vitronectin molecule, Our findings may shed new light to the activities of vitronectin and its binding t o cells, which could not be explained solely on the basis of the known heparin-binding domain. (C) 1997 Federation of European Biochemical S ocieties.