vWF receptor occupancy is proportional to platelet-aggregat- ing activity (21). Thus, the affinity of each form of FVIII/. vWF for the receptors on platelets should be ...
THEJOURNAL OF BIOLOGICAL CHEMISTRY Val. 255, No.21, Issue of November 10,pp. 10134-10139,1980 Printed m U.S.A.
Factor VIII/Von Willebrand Protein MODIFICATION OF ITS CARBOHYDRATE CAUSES REDUCED BINDING TO PLATELETS* (Received for publication, May 8, 1980, and in revised form, July 1, 1980)
Kuo-Jang Kao, SalvatoreV. Pizzo, and PatrickA. McKeeS From The Howard Hughes Medical Institute Laboratories, Department of Medicine and the Departments of Biochemistry and Pathology, Duke Uniuersity Medical Center, Durham, North Carolina 27710
It has been suggested that an abnormality in the essential for the formation of hemostatic platelet plugs at the carbohydrate structure of the blood clotting glycopro- transected end of small vessels. The molecular basis for the tein, human factor VIII/von Willebrand factor (FVIII/ two biological activities of this macromolecule remains unrevWF), maygive rise tothehemorrha.gicdisorder solved. The two biological activities can be dissociated from known as von Willebrand’s disease. More recently, we each other by treatment of FVIII/vWF with thrombin (2) or have reportedthat the sequential removal of sialicacid high ionic strength buffers (3-5). Some believe that dissociated and galactose from FVIII/vWF causes a progressive FVIII procoagulant activity is on a smaller molecule which diminution inthe ability of human FVIII/vWF t o sup- corresponds to
