Action of Poly-α-Amino Acids on Clotting of Fibrinogen by Thrombin. ∗

Abstract

Summary

1. The synthetic basic poly-α-amino acids, polylysine, polyornithine and polyarginine, accelerate conversion of fibrinogen to fibrin by thrombin; the acidic poly-α-amino acids, polyaspartic, polyglutamic and polycysteic acids, and also heparin, retard this reaction. 2. The acidic polyamino acids neutralize the clot accelerating activity of the basic polyamino acids. 3. The addition of polylysine makes possible the detection of concentrations of fibrinogen too low to be clotted by thrombin alone.