Conformation flexibility of avidin: the influence of biotin binding.

M.SOLEDAD CELEJ,; GUILLERMO GABRIEL MONTICH; D. FIDELIO, GERARDO

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2004 vol. 325 p. 922 - 922

igand binding to proteins is a key process in cell biochemistry. The interaction usually induces modifications in the unfolding thermodynamic parameters of the macromolecule due to the coupling of unfolding and binding equilibria. In addition, these modifications can be attended by changes in protein structure and/or conformational flexibility induced by ligand binding. In this work, we have explored the effect of biotin binding on conformation and dynamic properties of avidin by using infrared spectroscopy including kinetics of hydrogen/deuterium exchange. Our results, along with previously thermodynamic published data, indicate a clear correlation between thermostability and protein compactness. In addition, our results also help to interpret the thermodynamic binding parameters of the exceptionally stable biotin:AVD complex.