Clotting Factor X. Physiologic and Physico-Chemical Properties

Abstract

A new clotting factor, factor X, participating in blood thromboplastin formation, is demonstrated by matching experiments with various pathological sera. Possible influence of thrombin and factor VII is eliminated. The objection that factor X deficiency may be nothing else than a slight deficiency of factor IX (PTC) is in contradiction with the results obtained with purified factors. Factor X is present in normal serum and in hemophilia B-serum, absent in hepatitis-serum and in serum of Marcoumar- (dicoumarol derivative) treated patients. The affinity of factor X to BaSO4 is greater than that of factor VII and IX (PTC). This property is utilized for the purification of factor X. Factor X is not identical with PTA and the new factors of Spaet et al. and of Ratnoff et al.