Abstract

The binding of rhodamine B (RB) to human serum albumin (HSA) in the absence and presence of Cu²⁺ or Fe³⁺ under simulated physiological conditions was studied by using various biophysical methods for the first time. The results showed that the interaction between HSA and RB could spontaneously result in the formation of HSA-RB complex (namely, static quenching mechanism) through hydrophobic interactions and hydrogen bonds irrespective of the absence or presence of metal ions. The presence of metal ions led to the reduction of binding affinity of RB to HSA compared with no metal ions, which might result from the conformational change of HSA caused by the binding of metal ions. Furthermore, the analysis of UV-vis absorption, circular dichroism, synchronous fluorescence and three-dimensional fluorescence experiments demonstrated that the addition of RB induced conformational and microenvironmental changes of HSA without and with metal ions. In short, this work will be helpful to in-depth understand the transport mechanism and biological effect of RB and the effect of metal ions on the interaction of HSA-RB in vivo.

抽象的

在不存在和存在Cu ²⁺或Fe ³⁺的情况下，若丹明B（RB）与人血清白蛋白（HSA）的结合在模拟的生理条件下，首次使用各种生物物理方法进行了研究。结果表明，无论是否存在金属离子，HSA与RB之间的相互作用均可通过疏水相互作用和氢键自发形成HSA-RB配合物（即静态猝灭机理）。与没有金属离子相比，金属离子的存在导致RB与HSA的结合亲和力降低，这可能是由于金属离子的结合导致HSA的构象变化所致。此外，对紫外可见吸收，圆二色性，同步荧光和三维荧光实验的分析表明，添加RB会导致无金属离子和含金属离子的HSA的构象和微环境变化。简而言之，体内。