THE MECHANISM OF ACTION OF VITAMIN K-7 IS SIMILAR TO VITAMIN K1. TRADITIONALLY, K VITAMINS WERE RECOGNIZED AS THE FACTOR REQUIRED FOR COAGULATION, BUT THE FUNCTIONS PERFORMED BY THIS VITAMIN GROUP WERE REVEALED TO BE MUCH MORE COMPLEX. K VITAMINS PLAY AN ESSENTIAL ROLE AS COFACTOR FOR THE ENZYME G-GLUTAMYL CARBOXYLASE, WHICH IS INVOLVED IN CARBOXYLATION OF THE VITAMIN K-DEPENDENT PROTEINS [I.E., CONVERSION OF PEPTIDE-BOUND GLUTAMIC ACID (GLU) TO G-CARBOXY GLUTAMIC ACID (GLA)].
CARBOXYLATION OF VITAMIN K-DEPENDENT PROTEINS, KNOWN AS GLA-PROTEINS IS IMPORTANT AND SERVES AS A RECYCLING PATHWAY TO RECOVER VITAMIN K FROM ITS EPOXIDE METABOLITE (KO) FOR REUSE IN CARBOXYLATION. SEVERAL HUMAN GLA-CONTAINING PROTEINS SYNTHESIZED IN SEVERAL DIFFERENT TYPES OF TISSUES HAVE BEEN DISCOVERED: