Regulation of human erythrocyte glyceraldehyde-3-phosphate dehydrogenase by ferriprotoporphyrin IX

摘要: Erythrocyte glyceraldehyde-3-phosphate dehydrogenase (G3PD) is a glycolytic enzyme containing critical thiol groups and whose activity reversibly inhibited by binding to the cell membrane. Here, we demonstrate that insertion of ferriprotoporphyrin IX (FP) into red membranes exerts two opposite effects on membrane bound G3PD. First, partially inactivated through oxidation thiols. Dithiothreitol restores part activity, but some thiols are irreversibly oxidized or crosslinked products FP-induced lipid peroxidation. Second, G3PD modified activated displacement cytosol and/or release from its site.