羟丙基-β-环糊精对1-羟基芘与牛血清白蛋白相互作用的影响

Effects of Hydroxypropyl-β-cyclodextrin(HPCD) on the Interaction of 1-Hydroxypyrene with Bovine Serum Albumin

在模拟生理条件下,利用荧光光谱、圆二色光谱和紫外-可见吸收光谱探究了羟丙基-β-环糊精(HPCD)对1-羟基芘(1-OHPyr)与牛血清白蛋白(BSA)相互作用的影响及其相关机制.结果表明,291 K下HPCD可使1-OHPyr与BSA的结合常数降低为1.45×10~5L/mol;导致1-OHPyr-BSA体系中BSA的α-螺旋含量恢复,色氨酸(TRP)残基周围微环境的极性变化减弱;致使1-OHPyr及BSA的荧光寿命均延长,且二者的结合距离增大.初步研究结果表明,HPCD与1-OHPyr的包络作用是HPCD影响BSA与1-OHPyr结合的主要原因.

Fluorescence spectra, circular dichroism spectra and UV visible absorption spectra were employed to investigate the feasibility of regulating the interaction of 1-hydroxypyrene （1-OHPyr） with bovine serum albumin （BSA） using hydroxypropyl-β-cyclodextrin （HPCD） under simulated physiological conditions, and the related mechanism was preliminary discussed. The results showed that HPCD can inhibit the interaction of 1-OHPyr with BSA, and the binding constant of 1-OHPyr-BSA was decreased to 1.45× 105 L/mol at 291 K. HPCD can also restore the helix of BSA and inhibit the polarity changes of the local microenvironment of tryptophan（TRP） residues in BSA. HPCD can increase the fluorescence lifetimes of 1-OHPyr and BSA in 1-OHPyr-BSA system, meanwhile increase the binding distance of 1-OHPyr with BSA. The inclusion behavior of HPCD with 1-OHPyr was primarily the main reason why HPCD affected the binding of 1-OHPyr with BSA.