in the presence of thrombin-activated factor viii ( 1-5 units/ml ) and factor x ( 0.15-1.5 microm ) , the number of sites for factor ix was 316 ( +/- 50 ) with kd = 2.44 ( +/- 0.30 ) nm and for factor ixa 551 ( +/- 48 ) sites per platelet ( kd = 0.56 +/- 0.05 nm ) .
C0015491
factor ix
C0015494
factor ixa