Biologic Properties of Polynucleotides. II. The Anticoagulant Properties of Polynucleotides

Abstract

Abstract Polyinosinic and polyguanylic acids have been found to possess anticoagulant properties. Other synthetic homoribopolynucleotides, as well as naturally occurring RNAs and DNAs are devoid of such properties. Polyinosinic acid will prolong the silicone recalcification time, Quick one-stage prothrombin time, and Russel Viper Venom clotting time of human plasma, but will not affect the conversion of fibrinogen to fibrin by thrombin. Polyinosinic acid causes a delay in the rate of thrombin generation, and also inhibits thromboplastin generation. In the latter system polyguanylic acid is only ¼ as effective as polyinosinic acid. The anticoagulant properties of polyinosinic acid can be reduced or abolished by (1) high [Ca++] (2) hybrid helix formation with polyadenylic or polycytidylic acid, and (3) protamine sulphate. Mixed copolymers of inosinic and uridylic acids, or guanylic and uridylic acids having high (> 60 per cent) guanylic or inosinic acid contents possess graded anticoagulant properties. The anticoagulant properties of polynucleotides depend upon base composition and secondary structure.