Drotrecogin alfa is activated human protein C that is synthesized by recombinant DNA technology. It is a glycoprotein of approximately 55 kilodalton molecular weight, consisting of a heavy chain and a light chain linked by a disulfide bond. Drotrecogin alfa was withdrawn from the market after a major study indicated that it was not effective in improving outcomes in patients with sepsis. (en)
Activated protein C combines with protein S on platelet surfaces and then degrades factor Va and factor VIIIa, thereby reducing blood coagulability. (en)