Influence of oxidation and crosslinking on oxygen binding properties of mouse erythrocytes

Different chemical treatments for mouse erythrocyte modification has been u sed. Oxidation treatments with Ascorbate/Fe3+, a system able to react with intracellular proteins, produced a displacement of the O-2 binding equilibr ium curve to a higher affinity behaviour with loss of the haemoglobin coope rativity for oxygen binding. Incubation of mouse erythrocytes with diamide showed that at low reagent concentration (0.8 mM) no modification on oxygen binding equilibrium curves was observed. At higher reagent concentration ( 2.0 mM), an increased affinity and a disappearance of the cooperative behav iour can be observed. Additionally, crosslinking reactions on mouse erythro cytes with band 3 crosslinkers seemed to affect oxygen binding properties w hen used at a crosslinker concentration of 5 mM. Oxyhaemoglobin levels in c rosslinked and diamide-treated erythrocytes are similar to those found in c ontrol cells. In contrast, ascorbate/Fe3+ treatments produced an increment in the proportion of methaemoglobin, decreasing the oxyhaemoglobin levels i n these oxidized erythrocytes. Copyright (C) 2001 John Wiley & Sons, Ltd.