Distribution of fatty acids incorporated into triacylglycerols by microsome/cytosol preparations from adipose tissue

Microsome/cytosol preparations from adipose tissue of the mouse, pig, rat and chicken and from pig liver synthesize triacylglycerols containing a fatty acid distribution consistent with that in their respective fats. Since the incorporation of fatty acids depends on the presence of glycerol phospahte and no loss of tritium occurs during the incorporation of sn-[2-3 H]glycerol 3-phosphate into triacylglycerols, it would appear that the specific distribution is a property of the transacylases of the glycerophosphate pathway. The apparent Michaelis constant for sn-glycerol 3-phosphate, measured either by sn-glycerol 3-phosphate or palmitate incorporation, averaged 1.4-10-4 M both the mouse and pig adipose tissue enzyme systems.