Identification of natural killer enhancing factor as a major antioxidant in human red blood cells

Human natural killer enhancing factor genes (NKEF-A and B) share extensive homology with several genes from other organisms known to be induced by oxidative stress and to protect organisms and proteins from oxidative destruction. In this study, we have identified natural killer enhancing factor as an abundant protein in red blood cell cytosol. Highly purified natural killer enhancing factor blocks inactivation of enzymes by mixed metal-thiol oxidation. Thus, natural killer enhancing factor is a major antioxidant protecting red blood cells from oxidative injuries.