The Action of Crystalline Trypsin and Soybean Trypsin Inhibitor on the Clotting of Blood by Staphylocoagulase *

The mechanism of the coagulation of blood by staphylocoagulase and the relation of this process to physiological clotting present many unsolved problems. Evidence has been advanced for the concept that coagulase reacts with a plasma component (coagulase reacting factor CRF) which is distinct from prothrombin.5'4'1S1 The formation of an intermediate complex has been inferred from the shortening of the clotting time when some preparations of coagulase and plasma are incubated before the addition of fibrinogen.",6 A simplified representation of the reaction may thus be assumed to proceed along these lines: