Factor VIII and human platelet aggregation. I. Evience that the platelet aggregating activity of bovine factor VIII is a property of its 'carrier protein' subunit.
Bovine factor VIII is a potent inducer of aggregation of human platelets. Upon gel filtration of five-thousand-fold purified material in 0.5 M CaCl2, bovine factor VIII is separated into high and low molecular weight components; the former contains both a 'carrier protein' and platelet aggregating activity, the latter the procoagulant activity (low molecular weight factor VII, LMW-FVIII). Upon removal of Ca2+ ions, LMW-F VIII recombines with the 'carrier protein'. LMW-F VIII modifies aggregation by 'carrier protein', but not aggregation by undissociated bovine factor VII, adenosine-5'-diphosphate or adrenaline. This finding indicates that the platelet aggregating activity in indeed a property of the 'carrier protein'.
D000818:Animals; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000032:analysis*; D002417:Cattle; D005169:Factor VIII / Q000032:analysis* / Q000302:isolation & purification; D006801:Humans; D008970:Molecular Weight; D010974:Platelet Aggregation
D002352:Carrier Proteins; D005169:Factor VIII