A new anticoagulant-antidote pair: Control of thrombin activity by aptamers and porphyrins

Cationic porphyrins have been described to bind to G-quadruplexes with high affinities. In combination with G-quadruplex containing DNA aptamers that bind and inhibit the blood clotting factor thrombin, these molecules act as true antidotes that revert the anticoagulant activity of the aptamer. Porphyrins in concert with four-stranded aptamers therefore represent a novel anticoagulant/antidote class within the blood clotting cascade.