THE PREPARATION AND PROPERTIES OF PROTHROMBIN

Abstract

Howell''s method was found to be most efficient method of preparation. Prothrombin so prepared was activated to thrombin by CaCl2, CHCl3, C2H5OH, and also by standing in aqueous solution. Prothrombin is a pseudoglobulin and as such can be fractionally precipitated by (NH4)2SO4. Prothrombin on dialysis divides into a water-soluble (normal thrombin) and a water-insoluble (fibrinolytic thrombin) portion. Normal thrombin contained no P whereas the fibrinolytic type did. A provisional hypothesis is made that prothrombin is a complex molecule consisting of these 2 complex thrombin groups; and the activation of prothrombin consists in the precipitation of one of these groups as modified thrombin (water-insoluble and fibrinolytic), the other remaining in solution as normal or P-free thrombin.