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

Different chemical treatments for mouse erythrocyte modification has been used. Oxidation treatments with Ascorbate/Fe(3+), a system able to react with intracellular proteins, produced a displacement of the O(2) binding equilibrium curve to a higher affinity behaviour with loss of the haemoglobin cooperativity 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 behaviour can be observed. Additionally, crosslinking reactions on mouse erythrocytes with band 3 crosslinkers seemed to affect oxygen binding properties when used at a crosslinker concentration of 5 mM. Oxyhaemoglobin levels in crosslinked and diamide-treated erythrocytes are similar to those found in control cells. In contrast, ascorbate/Fe(3+) treatments produced an increment in the proportion of methaemoglobin, decreasing the oxyhaemoglobin levels in these oxidized erythrocytes.