Fractionation and reconstitution of vitamin K-dependent carboxylation activity in rat liver microsomes.

Attempts to purify the vitamin K-dependent carboxylation system from rat liver microsomes have not yet met with success. Purification procedures result in low yields of activity even after relatively mild separation methods. We have been able to demonstrate that one reason for these failures is that there are at least two components (which can be separated) necessary for the reaction. Recombination of the separated components is possible if the detergent (Triton X-100) concentration is lowered and ethylene glycol is added to the system. Under these conditions, vitamin K-dependent carboxylation of synthetic pentapeptide (Phe-Leu-Glu-Glu-Leu) can be totally reconstituted.