Protein C is a Vitamin K-dependent glycoprotein that is produced in the liver. Protein C is similar to the prothrombin group of blood coagulation factors in its primary structure. Normal protein C concentration in human plasma is approximately 1-3 ng/ml and the proenzyme concentration is approximately 3?g/ml. Protein C regulates blood coagulation by inactivating factors Va and VIIIa in the presence of calcium ions and phospholipids. Protein C deficiency is associated with inherited thrombophilia, ecchymotic skin lesions.
Background References
1. Couture P., Demers C., Morissette J., Delage R., Jomphe M., Couture L., Simard J.;"Type I protein C deficiency in French Canadians: evidence of a founder effect and association of specific protein C gene mutations with plasma protein C levels.";Thromb. Haemost. 80:551-556(1998).
2. Ireland H.A., Boisclair M.D., Taylor J., Thompson E., Thein S.L., Girolami A., de Caterina M., Scopacasa F., de Stefano V., Leone G., Finazzi G., Cohen H., Lane D.A.;"Two novel (R(-11)C; T394D) and two repeat missense mutations in the protein C gene associated with venous thrombosis in six kindreds.";Hum. Mutat. 7:176-179(1996).
3. Lind B., Schwartz M., Thorsen S.;"Six different point mutations in seven Danish families with symptomatic protein C deficiency.";Thromb. Haemost. 73:186-193(1995).
Sequence Similarity
Belongs to the peptidase S1 family.
Tissue Specificity
Plasma; synthesized in the liver.
Post-translational Modification
The vitamin K-dependent, enzymatic carboxylation of some Glu residues allows the modified protein to bind calcium.; N- and O-glycosylated. Partial (70%) N-glycosylation of Asn-371 with an atypical N-X-C site produces a higher molecular weight form referred to as alpha. The lower molecular weight form, not N-glycosylated at Asn-371, is beta. O-glycosylated with core 1 or possibly core 8 glycans.; The iron and 2-oxoglutarate dependent 3-hydroxylation of aspartate and asparagine is (R) stereospecific within EGF domains.; May be phosphorylated on a Ser or Thr in a region (AA 25-30) of the propeptide.
Western blot analysis of Vitamin K-dependent protein C on different lysates with Rabbit anti-Vitamin K-dependent protein C antibody (0812-6) at 1/2,000 dilution.