荧光光谱法研究健那绿B与牛血清白蛋白的相互作用

Study on the interaction of Janus green B and bovine serum albumin by fluorescence spectrometry

目的:研究健那绿B与牛血清白蛋白(BSA)之间的相互作用。方法:在模拟生理条件下,应用荧光光谱和紫外光谱法测定健那绿B与BSA的结合平衡常数Kb、结合位点数n,结合距离r及其热力学函数ΔH、ΔS、ΔG。结果:健那绿B与BSA在300 K,305 K和310 K时结合常数分别为1.5410×106,1.4077×106和1.3709×106L/mol,结合位点数n近似为1,结合距离r为1.55 nm。结论:健那绿B对BSA的荧光猝灭机制是以静态猝灭为主,二者之间作用力主要是静电引力。健那绿B的介入对BSA的构象影响较小。

Objective： To investigate the interaction between the Janus green B and bovine serum albumin （BSA）. Methods： Under the imitated physiological condition of animal body, the binding constants, number of binding site and the average binding distance between Janus green B and BSA, and corresponding thermodynamic parameters （AH, AS, AG） were investigated by fluorescence and UV -Visible spectroscopy. Results： The binding constants Kb between Janus green B and BSA at 300K, 305K and 301 K were 1. 5410 × 10^6, 1. 4077 × 10^6 and 1. 3709× 10^6 L/mol, respectively. The number of binding site （n） was about 1, and the average binding distance （r） was 1.55 nm. Conclusion： The fluorescence quenching mechanism of BSA by Janus green B was a static procedure. The binding force was considered to be mainly electrostatic attraction according to the thermodynamic parameters at different temperatures. The conformation of BSA was changed when the Janus green B was added.