Anticlotting properties of fragments D from human fibrinogen and fibrin.

It appeared from our previous studies that Ca2+ concentrations comparable to those occurring in blood protect the C-terminal part of the gamma-chain remnants of fibrin(ogen) fragments D against further plasmin attack. This study shows that purified fibrin(ogen) fragments D formed in the presence of Ca2+ ions have anticlotting activity in vitro, whereas shortening of the gamma-chain remnants leads to loss of such activity.