Reduced Triphosphopyridine Nucleotide Oxidase-catalyzed Alterations of Membrane Phospholipids

Abstract

Abstract A study of the TPNH-dependent utilization of the polyunsaturated fatty acids in the phospholipids of the microsomal membranes has shown that the process is enzymic in nature. TPNH is oxidized during the reaction and O2 is consumed. When all of the nucleotide is oxidized, both the lipid changes and the oxygen consumption stop. Addition of more TPNH (or a TPNH-regenerating system) reinitiates these activities. Parameters affecting the course of the reaction have been investigated, including studies with a number of inhibitors. The stoichiometry of the system has been determined with regard to TPNH, polyunsaturated fatty acid, and oxygen. Malondialdehyde is produced during this reaction, but it has been shown to be insignificant in terms of accounting for the polyunsaturated fatty acids which are utilized. The system bears some resemblance to that which synthesizes prostaglandins.