Studies on the acetylation of human fibrinogen

Abstract

Fibrinogen was acetylated under mild conditions at varying pH, giving materials of varying degrees of substitution very similar in physicochemical properties to the native protein. The clot-ting properties of the protein were modified by the degree of substitution. The material was no longer clottable by thrombin when the number of free amino groups substituted exceeded 35%. Acetylated fibrinogen inhibited the reaction between trombin and fibrinogen. This inhibition appears to be competi-tive. Although the acetylated fibrinogen did not form a clot when acted upon by thrombin, a peptide was split off and soluble poly-mers were formed.