crude protein preparation , obtained by ammonium sulfate precipitation ( 95 % saturation ) from the extract , exhibited high activity ( 0.81 units/mg protein ) towards a synthetic substrate of coagulation factor xiia , boc-gln-gly-arg-mca , and had also activity to form kallikrein in human plasma deficient in coagulation factor xii .
C0015527
coagulation factor xiia
C0015525
coagulation factor xii