Effect of ascorbate and cysteine on phospholipids of inner mitochondrial membranes

Abstract

Rat liver inner mitochondrial membranes incubated in the presence of ascorbate or cysteine undergo a selective degradation of phospholipids having polyunsaturated fatty acids in their molecules. Altered phospholipids with their saturated or mono­ unsaturated fatty acid remain bound to protein after the usual lipid ex'raction pro­ cedures.

Some phospholipids, such as cardiolipins, have in most of their molecules, exclu­ sively highly polyunsaturated fatty acids. Two groups of molecular species both in phosphatidylcholine and in phosphatidylethanolamine were found: one with highly unsaturated fatty acids and other with a polyunsaturated fatty acid together with a saturated fatty acid.