Investigating noncovalent interactions of rutin-serum albumin by capillary electrophoresis-frontal analysis.

The application of capillary electrophoresis-frontal analysis (CE-FA) to study noncovalent interaction between rutin and serum albumin (bovine serum albumin, BSA and human serum albumin, HSA) in phosphate buffer solution (67 mM, pH 7.4) at 37 degrees C is presented. Using fixed HSA or BSA concentration and increasing rutin concentration, the number of primary binding sites per HSA or BSA molecules, and the affinity constants were obtained. Both affinity constants are in a comparable range suggesting the similarity of affinity properties of HSA and BSA towards rutin. The proposed CE-FA method is simple, rapid and cost-effective which may be useful in further high-throughput protein binding studies of multi-components in traditional herbal medicines for pharmacological effect evaluations.