Generation of active forms of oxygen at Cu2+-catalyzed oxidation of haemoglobin--haemiluminescent study.

Haemiluminescent method is used to study the generation of active forms of oxygen upon Cu2+-catalyzed oxidation of guinea-pig oxyhaemoglobin. It has been found that Cu2+ markedly catalyses the oxidation of haemoglobin to methaemoglobin. The established inhibition of the oxidative process by the enzymes superoxide dismutase and catalase indicates the participation of O-2 and H2O2 in it. The haemiluminescent studies prove that O-2 and H2O2 are produced during the oxidation of haemoglobin. The production of active forms of oxygen is at least partly due to release of oxygen bound in the oxyhaemoglobin molecule in the form of superoxide radical. In addition to this, bivalent copper ions, oxidizing the haemoglobin SH-groups, are reduced to monovalent, which in their turn may reduce the molecular oxygen to O-2. The scheme of the primary acts of interaction in the Cu2+--HbO2--O2 system is proposed, leading to O-2 production, and through it--to other active oxygen forms.