Gamma-glutamyl carboxylase

Gamma-glutamyl carboxylase is an enzyme which oxidizes Vitamin K hydroquinone to Vitamin K 2,3 epoxide, while simultaneously adding CO2 to protein-bound glutamic acid (abbreviation = Glu) to form gamma-carboxyglutamic acid (also called gamma-carboxyglutamate, abbreviation = Gla). The carboxylation reaction will only proceed if the carboxylase enzyme is able to oxidize vitamin K hydroquinone to vitamin K epoxide at the same time; the carboxylation and epoxidation reactions are said to be coupled reactions. Gla domain-containing proteins depend on the carboxylation reaction for posttranslational modification.