Kinetics of Carbon Monoxide Binding to Fully and Partially Reduced Human Hemoglobin Valency Hybrids.

The kinetics of carbon monoxide binding following fast reduction of the valency hybrids α2+β2coand α2coβ2+ by hydrated electrons have been studied at different degrees of reduction. The results show that at pH 6.0 and 7.0 reduction of one heme group yields a species which reacts fast with carbon monoxide (rate constant of the order of 106 M-1 s-1. At pH 6.0 the intermediates α2coβ2 and α2β2co bind carbon monoxide with a rate characteristic of the T state. At pH 7.0 α2coβ2co is for the greater part in the T state, while in the case of α2β2co the R and the T state are about equally populated. [ABSTRACT FROM AUTHOR]