Factor Xa, Human Plasma

Factor Xa is a serine endoproteinase and a member of the S1 peptidase family. Factor Xa plays a critical role in the coagulation cascade by catalyzing the proteolytic conversion of prothrombin to active thrombin. Factor Xa’s prothrombin conversion activity is greatly enhanced in vivo when complexed with Factor V, calcium ions and phospholipids on the activated platelet surface.