Mudd_1997_Arch.Biochem.Biophys_341_251

Ozone was applied to sealed red cell ghost membranes at the rate of 95 nmol/min for periods up to 20 min. Acetylcholine esterase, on the outer face of the membrane, was inhibited up to 20%. Glyceraldehyde-3-phosphate dehydrogenase, on the inner surface of the membrane, was inhibited up to 87%. These differences reflected the inherent susceptibilities of the two enzymes and the presence or absence of the membrane barrier. Analysis of the total lipids of the ozone-treated ghosts showed no significant change in the distribution of lipid classes and no significant change in the fatty acid composition. There was no significant change in the fatty acid composition of the phosphatidylcholine fraction. There was a slight increase in 18:0 and 20:2 + 20:3 in the phosphatidylethanolamine fraction. There was no change in the molecular species distribution of the phosphatidylcholine or the phosphatidylethanolamine fraction. There was no evidence for the formation of the phospholipid ozonolysis product, 1-acyl-2-(9-oxo-nonanyl) derivatives of glyceryl-phosphoryl choline. There was no decline in the amount of cholesterol in the lipids derived from ozone-treated red cell membranes. Treatment of red cell ghost membranes and, by implication, the plasma membrane of cells by ozone therefore oxidizes peripheral proteins before it oxidizes lipids.