Vitamins, Harmones and Hemoglobin
Vit K dependent clotting factor (AIPG 2010)
|A||Factors V & VIII|
|B||Factors XI & XIII|
|C||Factors IX and X|
|D||Factors III + XI|
a. Vitamin K is involved in the carboxylation of certain glutamate residues in proteins to form gamma-carboxyglutamate residues (abbreviated Gla-residues).
b. The modified residues are often (but not always) situated within specific protein domains called Gla domains. Gla-residues are usually involved in binding calcium.
c. The Gla-residues are essential for the biological activity of all known Gla-proteins.
d. Till date 14 human proteins with Gla domains have been discovered, and they play key roles in the regulation of three physiological processes:
e. Blood coagulation: (prothrombin (factor II), factors VII, IX, X, protein C, protein S, and protein Z)
f. Bone metabolism: osteocalcin, also called bone Gla-protein (BGP), and matrix Gla protein (MGP).
g. Vascular biology