(*) Summary: The mean intrinsic thermodynamic quantity can be defined by considering the relative population of complex species in the solution and the value of intrinsic thermodynamic quantity corresponds to each step of ligation. In the present study, a new approach was introduced for analysis of experimental ligand binding data on basis of mean intrinsic thermodynamic quantities. In this regard, a deviation parameter was defined by comparing the non-interacting system with the cooperative interactive one. This parameter can be calculated just by estimation of the first binding constant. A set of relations between this deviation parameter and other binding characteristics, such as mean intrinsic Gibbs free energy of binding
and mean Gibbs free energy of site–site interaction, have been developed. This model presents binding mechanism in a unified way that is simple,yet stringent, more straightforward, more reliable and informative. This analyzing method has been successfully applied for evaluation of various systems such as oxygen binding to hemoglobin, laurate and warfarin binding to human serum albumin, and reveals some new biological features of these binding systems.

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(**) Biodata: Professor Abdol-khalegh Bordbar graduated in Biophysical Chemistry at the University of Tarbiat-Modarres with a distinguished degree in 1997. After graduating, he has worked as an Assistant Professor at the Department of Chemistry, University of Isfahan, Isfahan, Iran.
Since 2007 he is Professor at this university. He was distinguished researcher in Isfahan university in 2007. He has published more than 60 international papers in the area of Biophysical Chemistry and supervised many MSc and PhD students. His main interests are related to interaction of ligands to biomacromolecules, structure-function relationship in biological systems, protein stability and interaction of anticancer drugs with transport proteins and DNA.