OxyFile #132
Biochimica et Biophysica Acta, 691 (1982) 300-308
Elsevier Biomedical Press
Alterations of Red Cell Membrane Proteins and Hemoglobin Under
Natural and Experimental Oxidant Stress
N. Alloisio, D. Michelon, E. Bannier, A. Revol, Y. Beuzard, and J.
Delaunay
We compared on red cell membrane proteins and hemoglobin (Hb) the
effects of (i) natural oxidant stress that has been suggested to
occur in a variety of oxidative hemolytic anemias, and (ii)
experimental stress induced by hydrogen peroxide. SDS-polyacrylamide
gel electrophoresis was used for protein analysis. Under natural
conditions (thalassemias, hemoglobinopathies with Hb unstability), a
high molecular weight polymer (HMWP) and variable amounts of globin
mono- and dimers became apparent. Furthermore, a major 12 kDa
polypeptide, its dimer, and conspicuous spectrin degradation products
in the band 2.2-2.6 region occurred in a patient carrying the highly
unstable Hb Hammersmith. Under experimental conditions, incubation
of erythrocyte ghosts with H2O2 in the presence of minimal
concentration (25 uM) of Hb generated a HMWP at the expense of
membrane proteins, mainly spectrin. Incubation of a diluted (200 uM)
membrane-free hemolysate with H2O2 induced a HMWP, an array of globin
oligomers and a 12 kDa polypeptide similar to that mentionned above.
Therefore, the damage to the red cell membrane present in various
oxidative hemolytic anemias, including polypeptide polymerisation and
breakdown, can be produced by experimental oxidant stress. These
observations support the view that the alterations described in the
patients result directly from oxidative reactions. However, we did
not observe in the patient the sharp breakdown of polyunsaturated
fatty acids that was triggered in vitro by H2O2 in the presence of Hb
acting as a catalyst. In most cases, oligo- and polymers were
resistant to B-mercaptoethanol, and the chemical nature of the
underlying cross-links is discussed. To our knowledge, the 12 kDa
polypeptide, that we consider as arising from globin proteolysis, has
never been reported under pathological conditions.
Received September 14, 1981.
Revised manuscript received March 12, 1982
Key words: Erythrocyte membrane protein; Hemoglobin; Hemolytic
anemia; Oxidative stress