The role of iron in ascorbate-dependent deoxyribose degradation. Evidence consistent with a site-specific hydroxyl radical generation caused by iron ions bound to the deoxyribose molecule

In the presence of H2O2, ascorbate and phosphate buffer at pH 7.4, deoxyribose is degraded. Degradation is inhibited by catalase, mannitol, apotransferrin, apolactoferrin, or desferrioxamine. In the presence of sufficient apotransferrin to just inhibit deoxyribose degradation, reaction can be restored by adding more deoxyribose to the reaction mixture, but not by additional phosphate or ascorbate. It is suggested that deoxyribose degradation under our reaction conditions is achieved by a site-specific formation of hydroxyl radical using iron ions bound to the deoxyribose molecule. Spectrophotometric and kinetic evidence for the binding of iron ions to deoxyribose is presented.