Carbon Monoxide Binding in a Model of Hemoglobin Differs Between the T and the R Conformation
Carbon monoxide impedes the transport of oxygen in blood by competitive binding to the oxygen binding sites on hemoglobin. The affinity of these sites for carbon monoxide is much greater than that for oxygen. The ratio between carbon monoxide affinity and oxygen affinity (M) is usually assumed to have a fixed value (Haldane’s law), which is about 200. Reported values differ between authors (Douglas et al., 1912, Killick, 1936, Sendroy et al., 1929). However, this ratio is not a constant but depends on the level of saturation (Roughton, 1970) as well as on pH (Joels and Pugh, 1958). This means that simple procedures cannot be used to calculate the combined effects of simultaneous oxygen and carbon monoxide binding. Application of our mathematical model of hemoglobin (Zock, 1987) shows that this model can account for the above-mentioned phenomena in a straightforward way.
KeywordsCarbon Monoxide Competitive Binding Equilibrium Curve Oxygen Affinity Human Hemoglobin
Unable to display preview. Download preview PDF.
- Douglas, C.B., Haidane, J.S., and Haidane, J.B.S., 1912, The laws of combination of hemoglobin with carbon monoxide and oxygen, J. Physiol. (London)44: 275.Google Scholar
- Haidane, J.B.S., 1912, The dissociation of oxyhemoglobin in human blood during partial CO poisoning, J.Physiol. (London)45: XXII.Google Scholar
- Hlastala, M.P., H.P. McKenna, R.L. Franada, and Detter, J.C., 1976, Influence of carbon monoxide on hemoglobin-oxygen binding, J.Appl. Physiol.41: 893, 1976.Google Scholar
- Joels, N., and Pugh, L.G.C.E., 1958, The carbon monoxide dissociation curve of human blood. J. Physiol. (London)142: 63.Google Scholar
- Sendroy, J., Liu, S.H., and Van Slyke, D.D., 1929, The gasometric estimation of the relative affinity constant for carbon monoxide and oxygen in whole blood at 38 °C. Am. J. Physiol.90: 511.Google Scholar
- Zock, J.P., 1987, Mathematical model of the physiological properties of human hemoglobin. Proc. Kon. Ned. Acad. Wet.C90: 493.Google Scholar