Abstract
IN the sarcoplasmic reticulum (SR) of skeletal muscles ion transport involves an ATP driven calcium pump. The mechanism by which calcium ions are transported across the membrane is unknown. It is reasonable to assume, however, that some conformational changes in the transport protein are associated with this process. These changes might be more subtle than a complete rotation or translation of the protein1. The experiments described here have been designed to follow the modification of the protein conformation by measuring changes in strength of the protein's tryptophan fluorescence. We have observed transient changes of intensity induced by calcium ions and fluorescence fluctuations during one single pumping cycle of the enzyme. The kinetic pathway of the ATPase reaction which is linked to the ionic transport has been investigated previously by fast techniques, such as chemical quench-flow and fluorescence with calcium indicators2,3. We have attmpted to relate the conformational events observed to some steps of the proposed enzymatic schemes2–5.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Dutton, A., Rees, E. D. & Singer, S. J. Proc. natn. Acad. Sci. U.S.A. 73, 1532–1536 (1976).
Froehlich, J. P. & Taylor, E. N. J. biol. Chem. 250, 2013–2021 (1975).
Ikemoto, N. J. biol. Chem. 251, 7275–7277 (1976).
Carvalho, M. G. C., de Souza, D. G. & de Meis, L. J. biol. Chem. 251, 3629–3636 (1976).
Hasselbach, W. Enzyme 10, 431–467 (1975).
Dupont, Y. Biochem. biophys. Res. Commun. 71, 544–550 (1976).
Davies, D. G., Inesi, G. & Gulik-Krzywicki, R. Biochemistry 15, 1271–1276 (1976).
Dupont, Y. Eur. J. Biochem. 72, 185–190 (1977).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
DUPONT, Y., LEIGH, J. Transient kinetics of sarcoplasmic reticulum Ca2++Mg2+ ATPase studied by fluorescence. Nature 273, 396–398 (1978). https://doi.org/10.1038/273396a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/273396a0
This article is cited by
-
Mapping the ATP Binding Site in the Plasma Membrane H+-ATPase from Kluyveromyces lactis
Journal of Fluorescence (2014)
-
Intrinsic fluorescence as a probe of structure-function relationships in Ca2+-transport ATPases
Bioscience Reports (1996)
-
Fluorometric study on conformational changes in the catalytic cycle of sarcoplasmic reticulum Ca2+-ATPase
Bioscience Reports (1995)
-
How do Ca2+ ions pass through the sarcoplasmic reticulum membrane
Bioscience Reports (1995)
-
Fluorescence study on transmembrane Ca2+ gradient-mediated conformation changes of sarcoplasmic reticulum Ca2+-ATPase
Bioscience Reports (1994)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.