Chen Zhanfen, Zhang Shuping, Zhang Jian
Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi 435002, People’s Republic of China.
Biometals. 2015 Dec;28(6):1031-41. doi: 10.1007/s10534-015-9888-y.
The interaction of a mononuclear monofunctional anticancer Pt(II) complex, [PtLCl]Cl (L = 4′-bis(pyridine-2-ylmethyl)amino-2-phenylbenzothiazole) (1), and human serum albumin (HSA) was investigated under physiological conditions using UV–Vis absorption, circular dichroism, fluorescence, and synchronous fluorescence. The experimental results suggested that the Pt(II) complex could bind to HSA, induce conformation and microenvironmental changes of HSA with a moderate binding affinity, and quench the intrinsic fluorescence of HSA through a static quenching mechanism. The thermodynamic parameters, ΔG°, ΔH°, and ΔS°, calculated at different temperatures, indicated that the binding reaction was spontaneous and hydrophobic forces and π–π stacking played major roles in the association. Based on the number of binding sites, it was considered that one molecule of complex 1 could bind to a single site of HSA. In view of the results of site marker competition experiments, the reactive site of HSA to complex 1 mainly located in subdomain IIA (site I). Moreover, the binding distance, r, between donor (HSA) and acceptor (complex 1) was 4.69 nm according to Förster nonradiation energy transfer theory. The present study provides relevant and useful information that can be used for the design and application of mononuclear monofuctional Pt(II) complexes in biomedical sciences.
在生理条件下，采用紫外可见吸收光谱、圆二色光谱、荧光光谱和同步荧光光谱等方法，研究了单核单功能抗癌铂（II）配合物[PtLCl]Cl（L = 4′-双（吡啶-2-基甲基）氨基-2-苯基苯并噻唑）（1）与人血清白蛋白（HSA）的相互作用。实验结果表明，铂（II）配合物能与HSA结合，以中等结合亲和力诱导HSA的构象和微环境变化，并通过静态猝灭机制猝灭HSA的固有荧光。在不同温度下计算得到的热力学参数ΔG°、ΔH°和ΔS°表明，结合反应是自发的，疏水作用和π-π堆积在结合过程中起主要作用。根据结合位点的数量，认为配合物1的一个分子可以与HSA的一个位点结合。根据位点标记竞争实验的结果，HSA与配合物1的反应位点主要位于亚结构域IIA（位点I）。此外，根据Förster非辐射能量转移理论，供体（HSA）和受体（配合物1）之间的结合距离r为4.69 nm。本研究提供了相关且有用的信息，可用于单核单功能铂（II）配合物在生物医学科学中的设计和应用。
