Modified Protein C molecules have been made which substitute the gamma carboxylglutamic acid (Gla) region of another Vitamin K dependent protein, most preferably prothrombin, for the native region of the Protein C. The modified or chimeric protein C has advantages over the wild-type protein C since it is less sensitive to inhibition by natural inhibitors of protein C (which would otherwise decrease the ability of the protein C to act as an anticoagulant) and which does not need the same cofactors or same amounts of cofactors, and can therefore be effective in patients with lowered levels of the cofactors such as protein S or the lipids present in activated platelets such as phosphatidyl ethanolamine (PE).