Abstract: 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. A modified protein C molecules has been made which substitutes the gamma carboxyglutamic acid (Gla) region with the corresponding region of prothrombin. The modified or chimeric protein C has advantages over the wild-type protein C since it is less sensitive to inhibition by some natural antibody inhibitors of protein C (which would otherwise decrease the ability of the protein C to act as an anticoagulant) and which do 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 elevated levels in platelets such as phosphatidyl ethanolamine (PE). The anticoagulant activity of the chimera was tested in normal and factor V Leiden plasma.

Abstract: 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).

Abstract: An assay useful for detecting the propensity of patients for thrombotic disease, especially patients having the lupus anticoagulant or antiphospholipid antibodies, is described. The assay is conducted on patient and control plasma in the presence and absence of exogenous Protein C with a membrane source comprising phosphatidylethanolamine and phosphatidylserine. Patients at risk exhibit test results indicating activated Protein C function is inhibited.