Enzyme studies on human blood. XI. The isolation and characterization of thromboplastic cell and plasma components.

Abstract

Abstract Thromboplastic cell component (TCC) and thromboplastic plasma component (TPC) together but not separately have an activity identical with that of tissue thromboplastin lipoprotein in the extent and in the rate of prothrombin conversion. The results indicate a stoechiometric rather than a kinase-zymogen relationship between these two blood components. TCC is a lipoprotein isolated by high gravity centrifugation of blood cell extracts. TPC is found in the non-clottable globulins of plasma Fraction I. Therefore, all the biochemical factors essential for coagulation can be obtained individually in measurable quantities from human blood alone. A concept of the coagulation mechanism not involving tissue thromboplastin is presented and discussed.