Kinetics and mechanism of Ca2+ binding to arsenazo III and antipyrylazo III.

@article{Dorogi1984KineticsAM,
  title={Kinetics and mechanism of Ca2+ binding to arsenazo III and antipyrylazo III.},
  author={P. Dorogi},
  journal={Biochimica et biophysica acta},
  year={1984},
  volume={799 1},
  pages={
          9-19
        }
}
  • P. Dorogi
  • Published 1984
  • Chemistry, Medicine
  • Biochimica et biophysica acta
Equilibrium and temperature-jump spectrophotometric measurements were carried out on arsenazo III (Ar) and antipyrylazo III (Ap) in order to establish the kinetic reaction schemes for complexing of these dyes with Ca2+. The reaction media contained 30 mM Na2HPO4 as the buffer salt, at pH 7.4. Dependence of the relaxation rate of arsenazo III on dye and Ca2+ concentrations indicates the presence of both CaAr and CaAr2 complexes, with the CaAr2 form being responsible for the slow, 10-20 ms… Expand
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TLDR
The relatively slow rate-limiting step sets a limit for the use of arsenazo III to study the kinetics of Ca2+ processes in cell biology. Expand
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TLDR
The conclusion is that purified arsenazo III appears to serve as a convenient and reliable indicator for micromolar ionized Ca2+ concentrations in physiological salt solutions. Expand
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TLDR
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TLDR
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TLDR
The analytical method described in the preceding article was applied to spectrophotometric Ca2+-titrations of the metallochromic indicator arsenazo III (Ar) and it was determined that Ar forms 1:1,1:2 and 2 : 1 complexes with calcium. Expand
Affinity and stoichiometry of calcium binding by arsenazo III.
  • P. Bauer
  • Chemistry, Medicine
  • Analytical biochemistry
  • 1981
TLDR
Arsenazo III is a reliable calcium indicator if the experimental conditions, particularly pH, are well controlled and the p K Ca values are determined under the actual experimental conditions. Expand
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TLDR
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TLDR
Almost half of the bound arsenazo III is released from the particulate fraction and soluble proteins upon addition of 5 mM Ca2+, suggesting that the Ca-arsenazo complex has lower affinity for the protein binding sites than the free dye. Expand
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