Oxidation of hemoglobin to methemoglobin in intact erythrocyte by a hydroperoxide induces formation of glutathionyl hemoglobin and binding of alpha-hemoglobin to membrane

摘要

Biochemical consequences of oxidation of hemoglobin (Hb) in intact human erythrocytes were studied. The incubation of washed erythrocyte with 1 mM tert-butylhydroperoxide induced an increase in glutathionyl-Hb (G-Hb). The formation of G-Hb occurred linearly until 10 min in parallel with the formation of methemoglobin (metHb) after exhaustion of reduced glutathione. The results show that metHb, but not normal Hb, reacts with oxidized glutathione to form G-Hb. G-Hb was confirmed by immunoblotting with anti-glutathione antibody and the formation of G-Hb was accompanied by parallel decrease in beta-globin detected with a reversed phase HPLC. Electrophoretic studies showed time-dependent increase in membrane-associated alpha-Hb until 10 min, indicating that a part of impaired alpha-Hb bound to the membrane. Pre-beta-globin increased despite the decrease in beta-globin and a part of the increase was independent of the decrease in beta-globin. Pre-beta-globin reacted with anti-glutathione antibody, but it differs from G-Hb in many features. (C) 2003 Elsevier Inc. All rights reserved. [References: 36]