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. 1978 Aug;75(8):3747–3750. doi: 10.1073/pnas.75.8.3747

"Tension" on heme by the proximal base and ligand reactivity: conclusions drawn from model compounds for the reaction of hemoglobin.

V S Sharma, J F Geibel, H M Ranney
PMCID: PMC392863  PMID: 278985

Abstract

The kinetic data on model compounds of hemoglobin indicate that in oxyderivatives ligand dissociation rates are sensitive to the "tension" exerted by the proximal base on the metal-to-ligand bond; the corresponding rates for carboxy derivatives are not sensitive to the tension. It is suggested that the metal-to-ligand bond becomes weaker with increased "pull" (or tension) on Fe from the proximal base due to the steric and/or electronic interaction between the ligand, the porphyrin ring, and the proximal base. In model compounds the linear heme Fe-to-CO bound vis-a-vis the bent heme Fe-to-O2 bond probably makes such interactions less significant in carboxy derivatives. It is proposed that the kinetic alpha,beta-chain nonequivalence in Hb4(O2)4 is due to the difference in the tension in the two chains on Fe by the proximal base. The absence of alpha,beta-chain differences large enough to show up in CO dissociation rates from Hb4(CO)4 is explained on the basis of lack of sensitivity of the Fe-CO bound to tension from the proximal base. The implications of the results for the observed cooperative effects in ligand combination (for CO) and dissociation (for O2 and NO) rates of hemoglobin have also been discussed.

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Selected References

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

  1. Benko B., Vuk-Pavlović S. Nitrosyl haemoglobin: the NO-spin as a relaxation probe in the solvent-proton magnetic resonance experiment demonstrating the phosphate-induced widening of the haem-pocket. Biochem Biophys Res Commun. 1976 Aug 23;71(4):1303–1307. doi: 10.1016/0006-291x(76)90796-8. [DOI] [PubMed] [Google Scholar]
  2. Cassoly R., Gibson Q. Conformation, co-operativity and ligand binding in human hemoglobin. J Mol Biol. 1975 Jan 25;91(3):301–313. doi: 10.1016/0022-2836(75)90382-4. [DOI] [PubMed] [Google Scholar]
  3. Fermi G. Three-dimensional fourier synthesis of human deoxyhaemoglobin at 2-5 A resolution: refinement of the atomic model. J Mol Biol. 1975 Sep 15;97(2):237–256. doi: 10.1016/s0022-2836(75)80037-4. [DOI] [PubMed] [Google Scholar]
  4. 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]
  5. Gray R. D., Gibson Q. H. The effect of inositol hexaphosphate on the kinetics of CO and O 2 binding by human hemoglobin. J Biol Chem. 1971 Dec 10;246(23):7168–7174. [PubMed] [Google Scholar]
  6. MacQuarrie R., Gibson Q. H. Use of a fluorescent analogue of 2,3-diphosphoglycerate as a probe of human hemoglobin conformation during carbon monoxide binding. J Biol Chem. 1971 Sep 25;246(18):5832–5835. [PubMed] [Google Scholar]
  7. Maxwell J. C., Caughey W. S. An infrared study of NO bonding to heme B and hemoglobin A. Evidence for inositol hexaphosphate induced cleavage of proximal histidine to iron bonds. Biochemistry. 1976 Jan 27;15(2):388–396. doi: 10.1021/bi00647a023. [DOI] [PubMed] [Google Scholar]
  8. Moore E. G., Gibson Q. H. Cooperativity in the dissociation of nitric oxide from hemoglobin. J Biol Chem. 1976 May 10;251(9):2788–2794. [PubMed] [Google Scholar]
  9. Nishikura K., Sugita Y. The effect of inositol hexaphosphate on the absorption spectra of alpha and beta chains in nitrosyl hemoglobin. J Biochem. 1976 Dec;80(6):1439–1441. doi: 10.1093/oxfordjournals.jbchem.a131418. [DOI] [PubMed] [Google Scholar]
  10. Noble R. W., Gibson Q. H., Brunori M., Antonini E., Wyman J. The rates of combination of the isolated chains of human hemoglobin with oxygen. J Biol Chem. 1969 Jul 25;244(14):3905–3908. [PubMed] [Google Scholar]
  11. Olson J. S., Andersen M. E., Gibson Q. H. The dissociation of the first oxygen molecule from some mammalian oxyhemoglobins. J Biol Chem. 1971 Oct 10;246(19):5919–5923. [PubMed] [Google Scholar]
  12. Perutz M. F., Kilmartin J. V., Nagai K., Szabo A., Simon S. R. Influence of globin structures on the state of the heme. Ferrous low spin derivatives. Biochemistry. 1976 Jan 27;15(2):378–387. doi: 10.1021/bi00647a022. [DOI] [PubMed] [Google Scholar]
  13. 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]
  14. Sawicki C. A., Gibson Q. H. Properties of the T state of human oxyhemoglobin studies by laser photolysis. J Biol Chem. 1977 Nov 10;252(21):7538–7547. [PubMed] [Google Scholar]
  15. Sharma V. S., Everse J., Ranney H. M. Effect of urea on the kinetics of ligand combination reactions of hemoglobins A and H, alphaSH chains and myoglobin. J Mol Biol. 1975 Jul 5;95(3):385–393. doi: 10.1016/0022-2836(75)90197-7. [DOI] [PubMed] [Google Scholar]
  16. 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]
  17. Szabo A., Perutz M. F. Equilibrium between six- and five-coordinated hemes in nitrosylhemoglobin: interpretation of electron spin resonance spectra. Biochemistry. 1976 Oct 5;15(20):4427–4428. doi: 10.1021/bi00665a013. [DOI] [PubMed] [Google Scholar]
  18. Winterhalter K. H., Anderson N. M., Amiconi G., Antonini E., Brunori M. Functional properties of hemoglobin Zürich. Eur J Biochem. 1969 Dec;11(3):435–440. doi: 10.1111/j.1432-1033.1969.tb00793.x. [DOI] [PubMed] [Google Scholar]

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