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 K_a 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.

本研究的目的是通过多光谱方法研究考马斯亮蓝G-250（CBBG-250）与牛血清白蛋白（BSA）的相互作用。荧光数据表明，BSA-CBBG-250形成的复合物通过CBBG-250相互作用使BSA固有的荧光猝灭。BSA还可以与CBBG-250和以1：1摩尔比形成的CBBG-BSA复合物相互作用。UV-Vis结果显示，CBBG-250与BSA的表观结合（缔合）常数K _a为5.03×10 ⁴（298 K），3.04×10 ⁴（303 K），2.84×10 ⁴（308 K）和1.99 ×10 ⁴（313 K）L摩尔^-1分别在不同的温度下 焓变（△H）和熵变（△S）经计算分别为-45.32 kJ mol ^-1和-139.18 J mol ^-1 K ^-1，表明氢键和范德华力在互动。结果表明，考马斯亮蓝G-250中的二苯胺结构和氨基酸残基具有很强的范德华力。苯基磺酸基团与碱性氨基酸发生静电相互作用和氢键相互作用；化合物考马斯亮蓝G-250可与BSA形成稳定的复合物。