Wax Ester Synthesis by Carp Hepatopancreas Preparation

Abstract

Wax ester synthesis from different fatty acids by carp hepatopancreas preparations was studied. The main fatty acid moiety of wax and cholesteryl esters of hepatopancreas was docosahexaenoic acid (45.3%), which was not preferentially incorporated into wax esters. Wax ester synthesis with 10, 000×g supernatant showed the optimal activities between 30 to 35°C and pH 4 to 5. Wax ester synthesis from [1-14C] palmitic acid was promoted by increasing the addition of oleyl alcohol up to the concentration of 8mM, however, the incorporation into phospholipids was inhibited. By the addition of ATP wax ester synthesis from [1-14C] palmitic acid using the microsomal fraction was extremely activated. Polyunsaturated fatty acids such as 20 : 4, 20 : 5, and 22 : 6 were efficiently incorporated into phospholipids, but not into triacylglycerols, whereas rather considerable amounts of fatty acids of carbon length 18 such as 18 : 0, 18 : 1, 18 : 2, and 18 : 3 were mainly incorporated into triacylglycerols, but not into phospholipids. Some properties of wax ester synthesis by carp hepatopancreas preparations were discussed.