Effect of reduced vitamin K esters on vitamin K-dependent carboxylation.

The hypothesis of a vitamin K hydroquinone hemicarbonate as intermediate of vitamin K-dependent carboxylation of glutamic residues, has been examined, by testing several vitamin K hydroquinone esters as inhibitors of the reaction. Among the esters that have been synthetized, a monoacetate proved to be an inhibitor. Kinetic analysis shows that the inhibition is no competitive with respect to vitamin K.