Binding of ketoprofen with bovine serum albumin

Abstract

The binding of Ketoprofen, i.e 2-(3-benzoylphenyl) propionic acid, with bovine serum albumin, BSA, was investigated by equilibrium dialysis. Limiting the studies to low drug (10 to 100 μM) concentrations, the binding data correspond to a single set of binding sites, namely, the high-affinity sites. Scatchard and Klotz methods of analysis have been employed to determine the binding parameters for the high-affinity sites. The binding constant does not vary significantly with [BSA] in the concentration range 7·25 to 21·5 μM. The molar ratio, [drug]/[protein] is found to be a critical factor in determining the nature and number of binding sites. The quenching of intrinsic fluorescence of the protein at the emission wavelength of 346 nm indicates the presence of tryptophan in the binding site.