Changes in the Reactivity of Purified Prothrombin After Freeze Drying.

Abstract

Purified prothrombin can be dried from the frozen state without immediate loss of activity. Thereafter progressive loss of prothrombin activity occurs, characterized by refractivity to the action of Ca plus thromboplastin plus Ac-globulin. In about 1 yr. most of the prothrombin is altered and in addition some is insoluble in aqueous soln. Prothrombin altered as the result of the freeze drying technic can be activated autocatalytically in 25% Na citrate soln. The altered prothrombin has essentially the same electrophoretic properties as purified prothrombin and represents a derivative of prothrombin not previously described.