Abstract
Although the fixation of ligand to haemoglobin (Hb) is known to be accompanied by changes in protein conformation1 regulating the oxygen exchange in blood, the mechanism triggering these changes remains undecided2–4. We now report a dynamic approach to this problem using results obtained in a nanosecond laser photolysis study of carboxyhaemoglobin (HbCO) and its isolated subunits. The study is based on our previous observation5 of a structural evolution of free Hb after photodeligation, manifested through slight variations of the protein spectrum in the microsecond range. It is now found that the isolated subunits also show this behaviour. The duration of the spectral evolution is ∼2µs for the three proteins and the activation energy of the process ∼9 kcal mol−1. The spectral evolution is attributed to local conformation changes at the haem region, occurring during the structural relaxation of the freshly deliganded protein. The results for the isolated chains show that such changes exist even in the absence of the R-T transition.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Perutz, M. F., Muirhead, H., Cox, J. M. & Goaman, L. C. G. Nature 219, 131–139 (1968).
Perutz, M. F. Nature 228, 726–734 (1970).
Eisenberger, P., Shulman, R. G., Kincaid, B. M., Brown, G. S. & Ogawa, S. Nature 274, 30–34 (1978).
Little, R. G. & Ibers, J. A. J. Am. chem. Soc. 96, 4452–4463 (1974).
Alpert, B., El Mohsni, S., Lindqvist, L. & Tfibel, F. Chem. Phys. Lett. 64, 11–16 (1979).
Perutz, M. F. J. Crystal Growth 2, 54–56 (1968).
Geraci, G., Parkhurst, L. J. & Gibson, Q. H. J. biol. Chem. 244, 4664–4667 (1969).
Alpert, B., Lindqvist, L., El Mohsni, S. & Tfibel, F. in Interaction between Iron and Proteins in Oxygen and Electron Transport (ed. Ho, C.) (Elsevier, Amsterdam, in the press).
Greene, B. I., Hochstrasser, R. M., Weisman, R. B. & Eaton, W. A. Proc. natn. Acad. Sci. U.S.A. 75, 5255–5259 (1978).
Friedman, J. M. & Lyons, K. B. Nature 284, 570–572 (1980).
Anderson, L. J. molec. Biol. 79, 495–506 (1973).
Makinen, M. W. & Eaton, W. A. Nature 247, 62–64 (1974).
Gelin, B. R. & Karplus, M. Proc. natn. Acad. Sci. U.S.A. 74, 801–805 (1977).
Phillips, S. E. V. Nature 273, 247–248 (1978).
Gibson, Q. H. Biochem. J. 71, 293–303 (1959).
Sawicki, C. A. & Gibson, Q. H. J. biol. chem. 251, 1533–1542 (1976).
Drago, R. S., Beugelsdijk, T., Breese, J. A. & Cannady, J. P. J. Am. chem. Soc. 100, 5374–5382 (1978).
White, D. K., Cannon, J. B. & Traylor, T. G. J. Am. chem. Soc. 101, 2443–2454 (1979).
Lavalette, D., Tétreau, C. & Momenteau, M. J. Am. chem. Soc. 101, 5395–5401 (1979).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lindqvist, L., El Mohsni, S., Tfibel, F. et al. Transient haem–globin interactions in photodeligated carboxyhaemoglobin and subunits. Nature 288, 729–730 (1980). https://doi.org/10.1038/288729a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/288729a0
- Springer Nature Limited