Analysis of ligand binding process using binding capacity concept.

Binding capacity is the homotropic second derivative of the binding potential with respect to the chemical potential of the ligand. It provides a measure of steepness of the binding isotherm and represents the extent of cooperativity. In the present study, the shape of the binding capacity curve for various systems was investigated and the relation between binding capacity and the extent of cooperativity examined. In this regard, a novel linear graphical method was introduced for binding data analysis. The stoichiometry of binding and the extent of cooperativity can be determined by this method. This method has been successfully applied to various systems such as binding of oxygen to hemoglobin, warfarin to human serum albumin and dodecyltrimethylammonium bromide to alpha-amylase.