Fatty acid synthesis in aorta. Isolation of fatty acid synthetase from chicken aorta

Abstract

Fatty acid synthesis by subcellular fractions of human aorta was studied by measuring the incorporation of either radioactive acetyl-CoA or malonyl-CoA into long chain fatty acids. The high speed supernatant fraction contained fatty acid synthetase and was capable of de novo fatty acid synthesis. The fatty acid synthetase from chicken aorta was purified 800-fold from the high speed supernatant and was judged to be 10% pure at this level. Its molecular weight was estimated to be 450,000 on the basis of agarose gel filtration chromatography, while under dissociating conditions a molecular weight of 220,000 was obtained on sodium dodecyl sulphate disc gel electrophoresis. Fatty acid synthesis was dependent on acetyl-CoA, malonyl-CoA and NADPH. The major product was free palmitic acid. In enzymatic and physical characteristics the chicken aorta fatty acid synthetase strongly resembles the synthetase isolated from chicken liver. The two enzymes cross-react immuno-chemically and this homology provides the possibility of studying the synthesis and degradation of the aorta synthetase during the development of atherosclerosis.