Characteristics of synthesis of very-long-chain saturated and tetraenoic fatty acids in swine cerebral microsomes.
The elongation of arachidoyl-CoA (20:0-CoA) yielded 22:0 and 24:0 concomitantly, whereas the elongation of behenoyl-CoA (22:0-CoA) yielded only a negligible amount of 24:0 in adult swine cerebral microsomes. The dependence on time, pH, and the substrate concentrations were examined for the synthesis of 22:0 and 24:0 from 20:0-CoA. A microcomputer-aided simulation study suggested that there were two parallel pathways in the elongation of 20:0-CoA to 22:0 and 24:0. The elongation of 22:0-CoA could not be observed in adult swine cerebral microsomes; however, it was observed clearly in newborn swine and rat brain microsomes. A dilution experiment with the addition of cold 22:0-CoA in the reaction of elongation of 20:0-CoA confirmed the above suggestion that no intermediate 22:0 appeared during the synthesis of 24:0 from 20:0-CoA. The elongation of endogenous 20:4-CoA to 22:4 and 24:4 was examined in newborn swine cerebral microsomes, and the presence of two parallel pathways in the elongation of 20:4-CoA to 22:4 and 24:4 similar to those involved in the elongation of 20:0-CoA to 22:0 and 24:0 was suggested.
D000214:Acyl Coenzyme A / Q000378:metabolism; D000375:Aging; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D001921:Brain / Q000648:ultrastructure*; D005227:Fatty Acids / Q000096:biosynthesis*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D008861:Microsomes / Q000378:metabolism*; D051381:Rats; D013552:Swine
D000214:Acyl Coenzyme A; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; C042140:arachidoyl-coenzyme A; C007547:behenic acid; C010210:lignoceric acid