[Migration of parachloromercuribenzoic acid along the binding sites of hunan oxyhemoglobin]

Oxidation kinetics-characterized state of human oxyhemoglobin bound with p-chloromercuribenzoic acid (PCMB) (above 2 mole per tetramer) is changed during incubation at 20 degrees C. This suggests transfer of PCMB molecules from primary occupied centres to the secondary ones having higher affinity to PCMB. The same effect is observed at increased temperature without incubation. By means of gel-chromatography the hypothesis that the change of oxyhemoglobin state is accompanied by its increased equilibrium dissociation into dimers is acknowledge.