Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, PR China.
Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, PR China.
J Colloid Interface Sci. 2015 May 1;445:102-111. doi: 10.1016/j.jcis.2014.12.033. Epub 2014 Dec 24.
The binding interaction of anticancer drug (using 5-fluorouracil (FU) as an example) with the model protein human serum albumin (HSA), and the FU-binding-induced microenvironment alterations in subdomain IIA of HSA molecule were studied by a combination of spectroscopic techniques and molecular docking method. The results indicated that the nature of forces involved in binding interaction between HSA and FU molecule were mainly van der Waal's forces and hydrogen bonding interactions. These interactions resulted in the formation of FU-HSA complex, making the local microenvironment in subdomain IIA of the protein more hydrophobic than its native state. Moreover, the interaction caused the large conformation changes of HSA, leading to the increase of the compact α-helix structures at low concentration of FU (less than 150 μM). However, the high concentration of FU (higher than 150 μM) made the compact α-helix structure decreasing, probably due to the protein undergoing some sort of distortion. Molecular docking study revealed that FU could enter the inside a hydrophobic cavity of subdomain IIA (Sudlow's site I) in proximity of Trp214 residue with the formation of specific hydrogen bonding with Trp214 and Lys199 residues, causing the fluorescence quenching of Trp214 through a static quenching mechanism. The study essentially provides an effective way for investigating the microenvironment alterations of protein induced by the drug molecules, and this approach can further be used in development of biomedicines and assessment of the safety-engineered drug delivery.
本研究采用光谱技术和分子对接方法，研究了抗癌药物（以 5-氟尿嘧啶（FU）为例）与模型蛋白人血清白蛋白（HSA）的结合相互作用，以及 FU 结合诱导的 HSA 分子亚域 IIA 微环境变化。结果表明，HSA 与 FU 分子之间结合相互作用涉及的力的性质主要是范德华力和氢键相互作用。这些相互作用导致 FU-HSA 复合物的形成，使蛋白质亚域 IIA 的局部微环境比其天然状态更疏水。此外，这种相互作用导致 HSA 的构象发生大的变化，导致在 FU 的低浓度（小于 150μM）下，紧凑的α-螺旋结构增加。然而，高浓度的 FU（高于 150μM）使紧凑的α-螺旋结构减少，可能是由于蛋白质发生了某种变形。分子对接研究表明，FU 可以进入亚域 IIA（Sudlow 位点 I）的一个疏水腔中，靠近色氨酸 214 残基，与色氨酸 214 和赖氨酸 199 残基形成特定的氢键，通过静态猝灭机制导致色氨酸 214 的荧光猝灭。本研究为研究药物分子诱导的蛋白质微环境变化提供了一种有效的方法，该方法可进一步用于生物医学的开发和安全工程药物输送的评估。
