Aptamer RA36 inhibits of human, rabbit, and rat plasma coagulation activated with thrombin or snake venom coagulases.

RA36 DNA aptamer is a direct anticoagulant prolonging clotting time of human, rabbit, and rat plasma in the thrombin time test. Anticoagulant activity of RA36 is lower than that of recombinant hirudin. During inhibition of human plasma clotting activated with echitox (coagulase from Echis multisquamatus venom), the aptamer presumably binds to meisothrombin exosite I. The sensitivity of human plasma to the aptamer 5-fold surpasses that of rat plasma. Analysis of RA36 binding to coagulase of Agkistrodon halys venom (ancistron) is required for proving the effect of aptamer on polymerization of human fibrinogen.