Free radicals and protein degradation in human red blood cells.
Human red blood cells (RBC) were exposed to oxygen-based free-radicals, and other activated oxygen species generated during incubation with xanthine plus xanthine oxidase (X+XO). Oxygen-radical exposure induced up to 30 fold increases in human RBC protein degradation, compared to 12 fold increases in rabbit RBC protein degradation. Protein degradation increased as a function of X+XO, but demonstrated saturation kinetics at higher XO concentrations. The presence or absence of an energy substrate (glucose) had no effect on protein degradation, indicating the possible role of ATP-independent proteinolytic systems. It is proposed that human RBC proteins can be oxidatively damaged by certain free-radicals, and that the oxidized proteins are specifically recognized and degraded by intracellular proteinolytic systems.
D001786:Blood Glucose / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism; D003847:Deoxyglucose / Q000097:blood; D004905:Erythrocyte Aging; D005609:Free Radicals; D006801:Humans; D006868:Hydrolysis; D008054:Lipid Peroxides / Q000097:blood; D010084:Oxidation-Reduction; D014969:Xanthine Oxidase; D014970:Xanthines
D001786:Blood Glucose; D001798:Blood Proteins; D005609:Free Radicals; D008054:Lipid Peroxides; D014970:Xanthines; D003847:Deoxyglucose; D014969:Xanthine Oxidase