Poly(N-ethyl-4-vinylpyridinium) bromide as a potential probe to select heparin-like anticoagulant polyanions

Carboxymethyl dextran benzylamide sulfates compounds are polyanionic synthetic dextran derivatives with a random distribution of glucosyl units substituted with carboxymethyl, benzylamide, and sulfate groups. Two samples of derivatized dextrans with similar carboxymethyl and benzylamide contents, and with different sulfate content and one sample without benzylamide groups were prepared. The anticoagulant activity of the samples was estimated by the capacity to inhibit procoagulant activity of thrombin, following which the inhibition of this activity was monitored by addition of the polycation poly(N-ethyl-4-vinylpyridinium) bromide (PEVP). The potent inhibition by PEVP strongly suggests that the anticoagulant activity of the derivatives is attributable to a small portion of their overall negative charges. The comparison study of the samples implies that specific sites capable to bind thrombin are composed of rather small number of sulfate groups recognized and blocked by PEVP. These findings demonstrate high potential of PEVP as a probe for screening of heparin-like anticoagulant polyanions.