Degradation products of fibrinogen by elastase-like neutral protease from human granulocytes. Characterization and effects on blood coagulation in vitro

Abstract

The effects of elastase-like neutral protease isolated from human granulocytes on human fibrinogen were investigated. Dependent on enzyme concentration and time of incubation, the elastase-like protease induced a progressive degradation of fibrinogen. Analysis of the remaining polypeptide chains showed a high susceptibility of the Aα- and low susceptibility of the γ-chain of fibrinogen towards the proteolytic action of the enzyme. The split products were characterized by polyacrylamide gel electrophoresis and two-dimensional immunoelectrophoresis. They showed antigenic determinants of fibrinogen and of plasmin-induced proteolysis products D and E. The cleavage fragments isolated by gel chromatography had distinct molecular weights. Coagulability of fibrinogen by thrombin was inhibited according to the concentration of the protease and the time of incubation. Split products of fibrinogen with higher molecular weight prolonged the coagulation time of native fibrinogen, whereas low molecular weight fragments were ineffective.