IMPORTANCE OF PROTEASE INHIBITION IN STUDIES ON PURIFIED FACTOR-VIII (ANTIHAEMOPHILIC FACTOR)

Generally, factor VIII procoagulant activity may be dissociable from carrier protein (MW .apprx. 2 .times. 106) by agarose gel filtration, e.g., at high ionic strength. This phenomenon was reproduced. Addition of protease inhibitor (Trasylol) prevented the appearance of low MW peak of factor VIII procoagulant activity both at high ionic strength and elevated temperature (37.degree. C). Procoagulant activity and carrier protein (von Willebrand factor, factor VIII antigen) apparently are closely associated functional sites of native factor VIII macromolecule. Consequently, proteolytic degradation should be avoided in functional and structural studies on factor VIII and especially in preparing factor VIII concentrate for therapeutic use.