Studies of human hemoglobin intermediates the double mixing method for studying the reactions of the species Hb4(CO) and Hb4(CO)2
| Autor: | Vijay S. Sharma, G.A. Gilbert |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Carbon Monoxide
Macromolecular Substances Chemistry Stereochemistry chemistry.chemical_element Hemoglobin A Ligands Oxygen Hemoglobins Kinetics chemistry.chemical_compound Oxygen Consumption Reaction rate constant Carboxyhemoglobin Structural Biology Humans Physical chemistry Hemoglobin Saturation (chemistry) Molecular Biology Mathematics Carbon monoxide |
| Zdroj: | Journal of Molecular Biology. 166:677-684 |
| ISSN: | 0022-2836 |
| DOI: | 10.1016/s0022-2836(83)80292-7 |
| Popis: | Using the double mixing method we have studied the reactions of the partially liganded species (Hb4, Hb4L1, Hb4L2, Hb4L3) of normal human hemoglobin with carbon monoxide. In the first mixing, oxygen is removed from the species Hb4(O2) chi (CO) gamma and at the second mixing the species Hb4(CO) gamma reacts with CO. At 90% saturation of oxyHb with CO the main intermediate species are Hb4(CO)3 and Hb4(CO)2, and at 10% saturation Hb4 and Hb4(CO). The four CO-combination rate constants determined are: l'1 = 1 X 10(5) M-1 S-1, l'2 = 7 X 10(5) M-1 S-1, l'3 = 2 X 10(5) M-1 S-1 and l'4 = 4.8 X 10(6) M-1 S-1. The results indicate that there is no monotonic increase in the successive CO-combination rate constants. It is difficult to explain these results on the basis of the two-state model (Monod et al., 1965) or the stereochemical model of Perutz (1970). |
| Databáze: | OpenAIRE |
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