Abstract
The Ca2+-binding kinetics of fura-2 and azo-1 were studied using temperature-jump relaxation methods. In 140 mM KCl at 20 degrees C, the association and dissociation rate constants for fura-2 were 6.02 x 10(8) M-1s-1 and 96.7 s-1, respectively. The fura-2 kinetics were insensitive to pH over the range 7.4 to 8.4. Azo-1 was studied in 140 mM KCl, at pH 7.4, at 10 degrees and 20 degrees C. At 10 degrees C, azo-1 exhibited association and dissociation rate constants of 1.43 x 10(8) M-1s-1 and 777.9 s-1, respectively; while at 20 degrees C, the corresponding values were 3.99 x 10(8) M-1s-1 and 1,177 s-1. The kinetic results demonstrate that fura-2 and azo-1 are well suited to monitoring rapid changes in intracellular [Ca2+].
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Dorogi P. L., Rabl C. R., Neumann E. Kinetic scheme for Ca2+-arsenazo III interactions. Biochem Biophys Res Commun. 1983 Mar 29;111(3):1027–1033. doi: 10.1016/0006-291x(83)91403-1. [DOI] [PubMed] [Google Scholar]
- Grynkiewicz G., Poenie M., Tsien R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem. 1985 Mar 25;260(6):3440–3450. [PubMed] [Google Scholar]
- Jackson A. P., Timmerman M. P., Bagshaw C. R., Ashley C. C. The kinetics of calcium binding to fura-2 and indo-1. FEBS Lett. 1987 May 25;216(1):35–39. doi: 10.1016/0014-5793(87)80752-4. [DOI] [PubMed] [Google Scholar]
- Palade P., Vergara J. Stoichiometries of arsenazo III-Ca complexes. Biophys J. 1983 Sep;43(3):355–369. doi: 10.1016/S0006-3495(83)84359-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Provencher S. W. A Fourier method for the analysis of exponential decay curves. Biophys J. 1976 Jan;16(1):27–41. doi: 10.1016/S0006-3495(76)85660-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tsien R. Y. Intracellular measurements of ion activities. Annu Rev Biophys Bioeng. 1983;12:91–116. doi: 10.1146/annurev.bb.12.060183.000515. [DOI] [PubMed] [Google Scholar]
- Vergara J., Delay M. A transmission delay and the effect of temperature at the triadic junction of skeletal muscle. Proc R Soc Lond B Biol Sci. 1986 Oct 22;229(1254):97–110. doi: 10.1098/rspb.1986.0077. [DOI] [PubMed] [Google Scholar]