| [ Summary ] |
Vitamin K‒dependent proteins are characterized by multiple glutamyl residues which are γ‒carboxylated through post‒translational modification. At this time, 18 vitamin K‒dependent proteins have been identified in human body. This γ‒carboxylation is catalyzed by γ‒glutamyl carboxylase (GGCX) which requires vitamin K as a co‒factor. Vitamin K‒dependent proteins have highly conserved propeptides which have high degrees of affinity with GGCX and another highly conserved domain termed a "Gla domain", containing multiple glutamyl residues which can be carboxylated. The functions of vitamin K‒dependent proteins cover a surprisingly wide range of physiological and pathological phenomena such as blood coagulation, bone metabolism, diabetes, atherosclerosis, and suppression of malignant tumors. Many vitamin K‒dependent proteins are activated in γ‒carboxylation of Gla domains. However, some do not seem to require γ‒carboxylation to function. |