A Novel Lipid Hydroperoxide-Reducing Enzyme in Human Erythrocyte Membranes

Human erythrocyte membranes contain an enzyme capable of reducing lipid hydroperoxides at the expense of NADH. There is evidence that lipid peroxidation causes irreversible cross-linking of erythrocyte membrane proteins, possibly because of the spontaneous formation of malonaldehyde from some hydroperoxides. Such cross-linking could be of major importance for the recognition and removal of aged erythrocytes by the reticuloendothelial system. If this is so, the enzyme described in the present paper is likely to be important in ensuring normal longevity of the erythrocyte in the circulation by protecting the membrane proteins against hydroperoxide damage.