Binding nature and conformational alternations of bovine serum albumin upon interaction with synthesized LaF₃:Ce,Tb luminescent nanocrystals using multi-spectroscopic approach

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• 作者：Xingjia Guo^a ; Aijun Hao^b ; ^{hao1968@qq.com" class="auth_mail" title="E-mail the corresponding author} ; Qiong Wu^a ; Xin Diao^a ; Wenjing Liu^a ; Chenri Cong^a ; Ye Sun^a ; Liping Xu^a ; Jie Yao^a
• 关键词：LaF3 ; Ce ; Tb luminescent nanocrystals ; Bovine serum albumin ; Spectroscopic methods ; Potential toxicity
• 刊名：Journal of Luminescence
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：178
• 期：Complete
• 页码：210-218
• 全文大小：3360 K

文摘

Water-soluble LaF₃:Ce,Tb luminescent nanocrystals (RLNCs) were successfully fabricated according to previously reported literatures. The experimental results indicate that the as-prepared nanocrystals consist of well crystallized hexagonal phases, having a nearly spherical shape with an average diameter of 10 nm. The interaction of RLNCs with bovine serum albumin (BSA) was studied mainly via fluorescence quenching in combination with circular dichroism (CD) and ultraviolet–visible (UV–vis) absorption spectroscopy under imitated physiological conditions. The fluorescence titration results reveal that RLNCs could efficiently quench the intrinsic fluorescence of BSA mainly through a dynamic quenching procedure. The binding constant and the number of binding site at 300 K were estimated to be 4.606×10³ L mol⁻¹ and 0.98, respectively. Meanwhile, the thermodynamic parameters for RLNCs–BSA system were also determined, suggesting that the binding reaction between RLNCs and BSA took place spontaneously and was primarily driven by hydrophobic forces. Furthermore, it was found that the binding of RLNCs to BSA was mainly located in site I and the binding distance was estimated to be 3.0 nm. Finally, the synchronous fluorescence, three dimensional (3D) fluorescence, and CD spectroscopy were used to explore the conformational alterations of protein induced by RLNCs.