Systematically investigations of conformation and thermodynamics of HSA adsorbed to different sizes of CdTe quantum dots.
Systematically investigations of conformation and thermodynamics of HSA adsorbed to different sizes of CdTe quantum dots.
复制标题
DOI：
10.1016/j.colsurfb.2012.08.028
复制
发表时间：
2013-02
期刊：
影响因子：
--
通讯作者：
Qi Xiao;Shan Huang;Wei Su;Peiyuan Li;Jianqiang Ma;Fenping Luo;J. Chen;Yi Liu
中科院分区：
文献类型：
--
作者：
Qi Xiao;Shan Huang;Wei Su;Peiyuan Li;Jianqiang Ma;Fenping Luo;J. Chen;Yi Liu
荧光量子点在生物学和生物医学领域引起了广泛的关注。特别是，对于任何潜在的应用，量子点与一些生物分子的相互作用是非常重要的。本文采用紫外-可见吸收光谱、荧光光谱和圆二色光谱等方法，系统研究了生理条件下不同尺寸量子点与人血清白蛋白（HSA）的相互作用。测试了最大发射波长为520 nm（绿色QDs，GQD）、568 nm（黄色QDs，YQD）、620 nm（红色QDs，RQD）和680 nm（深红色QDs，CQD）的四种尺寸的CdTe QDs。荧光光谱结果表明，量子点能有效地猝灭人血清白蛋白的荧光强度，并具有一定的尺寸依赖关系。量子点与人血清白蛋白的结合是量子点与人血清白蛋白形成复合物的结果，静电相互作用对复合物的稳定起主要作用。计算了不同温度下的修正Stern-Volmer猝灭常数Ka和相应的热力学参数Δ H、Δ G和Δ S。用圆二色谱分析了量子点对人血清白蛋白构象的影响，结果表明，量子点越大，人血清白蛋白的生物活性越弱。
Fluorescent quantum dots (QDs) have attracted great attention in biological and biomedical fields. In particular, for any potential application, the interaction of QDs with some biomolecules is much important. Herein, the interactions between QDs with different sizes and human serum albumin (HSA) were systematically investigated by UV–vis absorption spectra, fluorescence spectra and circular dichroism (CD) spectra under the physiological conditions. Four sizes of CdTe QDs with maximum emission of 520nm (green QDs, GQDs), 568nm (yellow QDs, YQDs), 620nm (red QDs, RQDs) and 680nm (crimson QDs, CQDs) were tested. The fluorescence spectra results indicated that QDs could quench the fluorescence intensity of HSA effectively with a size-dependent relationship. The binding of QDs and HSA is a result of the formation of QDs–HSA complex and the electrostatic interaction plays a major role in stabilizing the complex. The modified Stern–Volmer quenching constants Kaat different temperatures and corresponding thermodynamic parameters ΔH, ΔG and ΔS were calculated. The conformational changes of HSA induced by QDs have been analyzed by CD spectra, and the results indicated that the biological activity of HSA was weakened in the present of QDs with bigger size.