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. 1988 Apr;85(7):2151–2155. doi: 10.1073/pnas.85.7.2151

The effect of quaternary structure on the kinetics of conformational changes and nanosecond geminate rebinding of carbon monoxide to hemoglobin.

L P Murray 1, J Hofrichter 1, E R Henry 1, M Ikeda-Saito 1, K Kitagishi 1, T Yonetani 1, W A Eaton 1
PMCID: PMC279947  PMID: 3353372

Abstract

To determine the effect of quaternary structure on the individual kinetic steps in the binding of carbon monoxide to the alpha subunit of hemoglobin, time-resolved absorption spectra were measured after photodissociation of carbon monoxide from a hemoglobin tetramer in which cobalt was substituted for iron in the beta subunits. Cobalt porphyrins do not bind carbon monoxide. Spectra were measured in the Soret region at room temperature after time delays that varied from a few nanoseconds to the completion of ligand rebinding at about 100 ms. The results show that the liganded molecule, alpha(Fe-CO)2 beta(Co)2, is in the R state, but can be almost completely switched into the T state by the allosteric effectors inositol hexaphosphate and bezafibrate. The geminate yield, which is the probability that the ligand rebinds to the heme from within the protein, is found to be 40% for the R state and less than 1% for the T state. According to the simplest kinetic model, these results indicate that carbon monoxide enters the protein in the R and T quaternary conformations at the same rate, and that the 60-fold decrease in the overall binding rate, of carbon monoxide to the alpha subunit in the T state compared to the R state is almost completely accounted for by the decreased probability of binding after the ligand has entered the protein. The results further suggest that the low probability for the T state results from a decreased binding rate to the heme and not from an increased rate of return of the ligand to the solvent.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Ansari A., DiIorio E. E., Dlott D. D., Frauenfelder H., Iben I. E., Langer P., Roder H., Sauke T. B., Shyamsunder E. Ligand binding to heme proteins: relevance of low-temperature data. Biochemistry. 1986 Jun 3;25(11):3139–3146. doi: 10.1021/bi00359a011. [DOI] [PubMed] [Google Scholar]
  2. Arnone A., Perutz M. F. Structure of inositol hexaphosphate--human deoxyhaemoglobin complex. Nature. 1974 May 3;249(452):34–36. doi: 10.1038/249034a0. [DOI] [PubMed] [Google Scholar]
  3. Austin R. H., Beeson K. W., Eisenstein L., Frauenfelder H., Gunsalus I. C. Dynamics of ligand binding to myoglobin. Biochemistry. 1975 Dec 2;14(24):5355–5373. doi: 10.1021/bi00695a021. [DOI] [PubMed] [Google Scholar]
  4. Chernoff D. A., Hochstrasser R. M., Steele A. W. Geminate recombination of O2 and hemoglobin. Proc Natl Acad Sci U S A. 1980 Oct;77(10):5606–5610. doi: 10.1073/pnas.77.10.5606. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Fermi G., Perutz M. F., Dickinson L. C., Chien J. C. Structure of human deoxy cobalt haemoglobin. J Mol Biol. 1982 Mar 15;155(4):495–505. doi: 10.1016/0022-2836(82)90483-1. [DOI] [PubMed] [Google Scholar]
  6. Friedman J. M., Scott T. W., Fisanick G. J., Simon S. R., Findsen E. W., Ondrias M. R., Macdonald V. W. Localized control of ligand binding in hemoglobin: effect of tertiary structure on picosecond geminate recombination. Science. 1985 Jul 12;229(4709):187–190. doi: 10.1126/science.4012316. [DOI] [PubMed] [Google Scholar]
  7. Gibson Q. H., Ikeda-Saito M., Yonetani T. Geminate reactions of oxygen and nitric oxide with the alpha and beta subunits of Fe-Co hybrid hemoglobins. J Biol Chem. 1985 Nov 15;260(26):14126–14131. [PubMed] [Google Scholar]
  8. Gibson Q. H. The reaction of oxygen with hemoglobin and the kinetic basis of the effect of salt on binding of oxygen. J Biol Chem. 1970 Jul 10;245(13):3285–3288. [PubMed] [Google Scholar]
  9. Henry E. R., Sommer J. H., Hofrichter J., Eaton W. A. Geminate recombination of carbon monoxide to myoglobin. J Mol Biol. 1983 May 25;166(3):443–451. doi: 10.1016/s0022-2836(83)80094-1. [DOI] [PubMed] [Google Scholar]
  10. Hofrichter J., Henry E. R., Sommer J. H., Deutsch R., Ikeda-Saito M., Yonetani T., Eaton W. A. Nanosecond optical spectra of iron-cobalt hybrid hemoglobins: geminate recombination, conformational changes, and intersubunit communication. Biochemistry. 1985 May 21;24(11):2667–2679. doi: 10.1021/bi00332a012. [DOI] [PubMed] [Google Scholar]
  11. Hofrichter J., Sommer J. H., Henry E. R., Eaton W. A. Nanosecond absorption spectroscopy of hemoglobin: elementary processes in kinetic cooperativity. Proc Natl Acad Sci U S A. 1983 Apr;80(8):2235–2239. doi: 10.1073/pnas.80.8.2235. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hopfield J. J., Shulman R. G., Ogawa S. An allosteric model of hemoglobin. I. Kinetics. J Mol Biol. 1971 Oct 28;61(2):425–443. doi: 10.1016/0022-2836(71)90391-3. [DOI] [PubMed] [Google Scholar]
  13. Ikeda-Saito M., Yamamoto H., Yonetani T. Studies on cobalt myoglobins and hemoglobins. Electron paramagnetic resonance investigation of iron-cobalt hybrid hemoglobins and its implication for the heme-heme interaction and for the alkaline Bohr effect. J Biol Chem. 1977 Dec 10;252(23):8639–8644. [PubMed] [Google Scholar]
  14. Ikeda-Saito M., Yonetani T. Studies on cobalt myoglobins and hemoglobins. XI. The interaction of carbon monoxide and oxygen with alpha and beta subunits in iron-cobalt hybrid hemoglobins. J Mol Biol. 1980 Apr 25;138(4):845–858. doi: 10.1016/0022-2836(80)90068-6. [DOI] [PubMed] [Google Scholar]
  15. MONOD J., WYMAN J., CHANGEUX J. P. ON THE NATURE OF ALLOSTERIC TRANSITIONS: A PLAUSIBLE MODEL. J Mol Biol. 1965 May;12:88–118. doi: 10.1016/s0022-2836(65)80285-6. [DOI] [PubMed] [Google Scholar]
  16. Perutz M. F. Stereochemistry of cooperative effects in haemoglobin. Nature. 1970 Nov 21;228(5273):726–739. doi: 10.1038/228726a0. [DOI] [PubMed] [Google Scholar]
  17. Sawicki C. A., Gibson Q. H. Dependence of the quantum efficiency for photolysis of carboxyhemoglobin on the degree of ligation. J Biol Chem. 1979 May 25;254(10):4058–4062. [PubMed] [Google Scholar]
  18. Sawicki C. A., Gibson Q. H. Quaternary conformational changes in human hemoglobin studied by laser photolysis of carboxyhemoglobin. J Biol Chem. 1976 Mar 25;251(6):1533–1542. [PubMed] [Google Scholar]
  19. Sharma V. S., Schmidt M. R., Ranney H. M. Dissociation of CO from carboxyhemoglobin. J Biol Chem. 1976 Jul 25;251(14):4267–4272. [PubMed] [Google Scholar]
  20. Shulman R. G., Hopfield J. J., Ogawa S. Allosteric interpretation of haemoglobin properties. Q Rev Biophys. 1975 Jul;8(3):325–420. doi: 10.1017/s0033583500001840. [DOI] [PubMed] [Google Scholar]
  21. Szabo A., Karplus M. A mathematical model for structure-function relations in hemoglobin. J Mol Biol. 1972 Dec 14;72(1):163–197. doi: 10.1016/0022-2836(72)90077-0. [DOI] [PubMed] [Google Scholar]
  22. Szabo A. Kinetics of hemoglobin and transition state theory. Proc Natl Acad Sci U S A. 1978 May;75(5):2108–2111. doi: 10.1073/pnas.75.5.2108. [DOI] [PMC free article] [PubMed] [Google Scholar]

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