studies of competition for bound factor ixa by excess unlabeled factor ix or factor ixa , and direct 125i-labeled factor ixa binding studies in the presence of large molar excesses of factor ix , confirmed the conclusion from these studies that factor ix and factor ixa share approximately 300 low-affinity binding sites per thrombin-activated platelet in the presence of ca2+ and in the absence of factor viii and factor x , with an additional 200-250 sites for factor ixa with kd ( app ) similar to that for factor ix .
C0015494
factor ixa
C0015491
factor ix