The roles of factor Va and protein S in formation of the activated protein C/protein S/factor Va inactivation complex

Activated protein C (APC)-mediated inactivation of factor (F)Va is greatly enhanced by protein S. For inactivation to occur, a trimolecular complex among FVa, APC, and protein S must form on the phospholipid membrane. However, direct demonstration of complex formation has proven elusive.To elucidate the nature of the phospholipid-dependent interactions among APC, protein S, and FVa.We evaluated binding of active site blocked APC to...