Investigation of interaction between bovine serum albumin and drugs by fluorescence spectrometry

Abstract

A new method for determining the binding constants and the number of binding sites of protein with drugs was developed. The binding constant and site number for the non-covalent complex were directly calculated based on the concentration of free drugs obtained by fluorescence spectrometry. The thiol resin was used for the immobilization of protein. The present method was applied to the investigation of the interaction between bovine serum albumin (BSA) and drugs, including arctiin and liquiritin. The binding constant and site number for BSA and arctiin were found to be 2.228 × 10⁵ L mol⁻¹ and 15.7, and those for BSA and liquiritin were 7.28 × 10⁴ L mol⁻¹ and 21.0, respectively. The obtained results confirmed that the present method is a good alternative for the determination of the binding constant and site number for the molecular interaction.