Bimodal frequency distribution of rat hepatic vitamin K-dependent carboxylation rate.
The time course of vitamin K-dependent carboxylation was studied in an in vitro rat hepatic microsomal system. This method is based on incorporation of radiolabelled CO2 into endogenous substrate proteins. Forty rats were studied in order to characterize the intrinsic formation rate (V/KM) of carboxylated vitamin K-dependent proteins and the maximum amount of endogenous substrate available for vitamin K-dependent carboxylation (P infinity; normalized for the total amount of microsomal protein harvested). The frequency distributions of V/KM and P infinity values were both well described as the sum of two Gaussian components, each representing about 40% and 60% of the populations.
D000818:Animals; D007700:Kinetics; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014812:Vitamin K / Q000494:pharmacology*
D011506:Proteins; D014812:Vitamin K