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Thermodynamics of effector binding to hemocyanin: influence of temperature
Archives of Biochemistry and Biophysics (2009)
  • Ariane Pott
  • Michael A Menze, University of Louisville
  • Manfred K. Grieshaber
Hemocyanins are allosterically regulated oxygen carriers freely dissolved in the blood of many crustaceans. The natural modulator urate accumulates under hypoxic conditions in the hemolymph of Homarus vulgaris, and increases the oxygen affinity of the respiratory pigment. Other non-physiological effectors such as caffeine, dimethylxanthines and methylxanthines are also known to modulate the oxygen-binding properties of hemocyanin. In order to gain insight into the thermodynamic driving forces of these interactions we analyzed the binding of several urate analogs to dodecameric hemocyanin at different temperatures by employing isothermal titration calorimetry (ITC). All investigated non-physiological effectors including caffeine, dimethylxanthines and methylxanthines bind exothermically to hemocyanin and the binding processes are enthalpy driven. Furthermore, we demonstrated a strong temperature dependent binding of caffeine and dimethylxanthines to the hemocyanin of the European lobster and could show that the binding properties of the effectors to the urate-binding site depend on the hydrophobicity of a given molecule.
  • Lobster,
  • Allosteric model,
  • Titration calorimetry,
  • Homarus vulgaris,
  • Protein interaction,
  • Ligand,
  • Hemocyanin
Publication Date
March, 2009
Publisher Statement
This manuscript has been published in the journal Archives of Biochemistry and Biophysics:
Citation Information
Ariane Pott, Michael A Menze and Manfred K. Grieshaber. "Thermodynamics of effector binding to hemocyanin: influence of temperature" Archives of Biochemistry and Biophysics Vol. 483 Iss. 1 (2009)
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