Study on Interaction of Coomassie Brilliant Blue G-250 with Bovine Serum Albumin by Multispectroscopic

Abstract

Aim of present study was to investigate the interaction of coomassie brilliant blue G-250 (CBBG-250) with bovine serum albumin (BSA) by the multispectroscopic methods. Fluorescence-data showed that the complex of BSA-CBBG-250 forming made the intrinsic fluorescence quenching of BSA by CBBG-250 interaction. BSA also could interact with CBBG-250 and the CBBG-BSA complexes formed in a molar ratio of 1:1. UV–Vis results displayed that the apparent binding (association) constant Ka of CBBG-250 with BSA was 5.03 × 104 (298 K), 3.04 × 104 (303 K), 2.84 × 104 (308 K) and 1.99 × 104 (313 K) L mol−1 at different temperatures, respectively. The enthalpy change (△H) and entropy change (△S) were respectively calculated to be − 45.32 kJ mol−1 and − 139.18 J mol−1 K−1, indicating that the hydrogen bonds and Van der Waals forces played dominant roles in the interaction. The results showed that the diphenylamine structure and amino acid residues in the Coomassie Brilliant Blue G-250 had a strong Van der Waals force. The phenyl sulphonic acid group undergoes electrostatic interactions and hydrogen bond interactions with basic amino acids; the compound Coomassie Brilliant Blue G-250 can form a stable complex with BSA.