ENZYMATIC-SYNTHESIS OF WAX ESTERS BY A MICROSOMAL PREPARATION FROM THE HONEYBEE APIS-MELLIFERA L

A microsomal preparation obtained from the abdomens of honeybee A. mellifera incorporated long chain primary alcohols, fatty acids and the acyl group from acyl-CoA into cuticular wax monoesters. The incorporation of [1-14C]-palmitate into monoester was stimulated by ATP, CoA, and MgCl2, and the addition of palmitoyl-CoA caused a 5 fold increase in monoester synthesis using [R-3H]-tetracosanol as the labeled substrate. The mechanism of monoester synthesis involved the transfer of an acyl group from acyl-CoA to a primary alcohol. The addition of palmitoyl-CoA at concentrations up to 100 .mu.M caused an increase in the rate of monoester synthesis, where at concentrations above 100 .mu.M, palmitoyl-CoA markedly inhibited monoester formation. An apparent Km for tetracosanol was calculated from a double reciprocal plot to be 9 .times. 10-4 M. Although the naturally occurring primary alcohols in the monoesters of the cuticular wax from the honeybee range in chain length from C24 to C32, labeled primary alcohols of 16, 18, 24 and 28 carbons were readily incorporated into monoester, with the C16 and C18 components incorporated at higher rates then the C24 and C28 homologues. A C27 secondary alcohol was not incorporated into wax esters.