Affinity of a mononuclear monofunctional anticancer Pt(II) complex to human serum albumin: a spectroscopic approach

作者：Chen, Zhanfen^*; Zhang, Shuping; Zhang, Jian

来源：Biometals, 2015, 28(6): 1031-1041.

DOI：10.1007/s10534-015-9888-y

• Monofunctional Pt(II) complex
• Human serum albumin
• Fluorescence quenching
• Anticancer metallodrugs

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, Delta G degrees, Delta H degrees, and Delta S degrees, calculated at different temperatures, indicated that the binding reaction was spontaneous and hydrophobic forces and pi-pi 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 Forster 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.

• 出版日期2015-12
• 单位湖北师范大学