A comparison between vitamin K-dependent carboxylase from normal and warfarin-treated cows

Detergent-solubilized microsomal preparations that catalyze the vitamin K-dependent .gamma.-carboxylation of glutamic acid residues in peptide and protein substrates, were obtained from the livers of normal and warfarin-treated cows. The preparations from warfarin-treated animals contained more endogenous substrate than those from normal cows, but otherwise the 2 preparations were indistinguishable. The enzymes vitamin K reductase and .gamma.-glutamyl carboxylase, may function independently of each other in this system. They are linked so that the reduced vitamin K produced by the former enzyme can be used immediately by the latter.