Luminescence of peptide‐bound terbium ions Determination of binding constants
- 22 April 1991
- journal article
- Published by Wiley in FEBS Letters
- Vol. 282 (1) , 143-146
- https://doi.org/10.1016/0014-5793(91)80464-e
Abstract
Luminescence of Tb3+ ions bound to a calmodulin fragments has been studied. It is shown that during their lifetime excited ions dissociate from the peptide. If concentration of free peptide is high enough they can be coordinated again. As a consequence, observed terbium luminescence lifetime and intensity depends not only on binding equilibrium, but also on concentration or free peptide molecules. In such a system terbium binding constant cannot be correctly determined by simple steady‐state measurements of luminescence intensities. Instead, terbium luminescence decay curves measured at various peptide concentrations must be analysed. Such an analysis has been made for a fragment of the IIIrd calcium binding domain of rat testis calmodulin. Rate constant or terbium association and the equilibrium binding constant corresponding to the best fit of theoretical functions to experimental points have been determined.Keywords
This publication has 10 references indexed in Scilit:
- Peptides related to the calcium binding domains II and III of calmodulinInternational Journal of Peptide and Protein Research, 2009
- Conformation and ion binding properties of peptides related to calcium binding domain III of bovine brain calmodulinBiopolymers, 1989
- Conformational properties of Ca2+-binding segments of proteins from the troponin C superfamilyBiophysical Chemistry, 1988
- Structural and biological studies on synthetic peptide analogues of a low-affinity calcium-binding site of skeletal troponin CBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1987
- Synthetic peptide analogs of skeletal troponin C: Fluorescence studies of analogs of the low-affinity calcium-binding site IIArchives of Biochemistry and Biophysics, 1983
- Nuclear magnetic resonance determination of metal-proton distances in the EF site of carp parvalbumin using the susceptibility contribution to the line broadening of lanthanide-shifted resonancesBiochemistry, 1980
- Lanthanide ion probes of structure in biology. Laser-induced luminescence decay constants provide a direct measure of the number of metal-coordinated water moleculesJournal of the American Chemical Society, 1979
- Terbium replacement of calcium in parvalbuminJournal of Molecular Biology, 1978
- Terbium(III) emission as a probe of calcium(II) binding sites in proteinsJournal of the American Chemical Society, 1976
- Study of the nature of the metal-binding sites and estimate of the distance between the metal-binding sites in transferrin using trivalent lanthanide ions as fluorescent probesBiochemistry, 1971