He Jiawei, Li Shanshan, Xu Kailin, Tang Bin, Yang Hongqin, Wang Qing, Li Hui
College of Chemical Engineering, Sichuan University, Chengdu 610065, China.
College of Chemical Engineering, Sichuan University, Chengdu 610065, China.
Food Chem. 2017 Apr 15;221:650-656. doi: 10.1016/j.foodchem.2016.11.124. Epub 2016 Nov 23.
The interaction between carthamin and human serum albumin (HSA) was investigated by multiple spectroscopic analyses, surface plasmon resonance (SPR), isothermal titration microcalorimetry (ITC), and molecular docking studies. Fluorescence lifetime measurements implied that carthamin quenched the intrinsic fluorescence of HSA with the formation of a new complex via static mode. Binding affinities regarding this interaction were obtained from SPR analysis. Results demonstrated that carthamin could form a 1:1 complex with HSA at the binding affinity of K=8.726×10M and that a high temperature was unfavourable for the interaction. ITC analyses and molecular docking results illustrated that HSA shaped a proper cavity (site I) to embed the whole carthamin molecule and that the complex was formed depending on intermolecular forces, including hydrophobic interaction, hydrogen bonding, and electrostatic force. Moreover, circular dichroism and 3D fluorescence demonstrated that carthamin slightly disturbed the microenvironment of amino residues and affected the secondary structure of HSA.
通过多种光谱分析、表面等离子体共振（SPR）、等温滴定量热法（ITC）和分子对接研究，对红花苷与人血清白蛋白（HSA）之间的相互作用进行了研究。荧光寿命测量表明，红花苷通过静态模式猝灭了HSA的固有荧光，并形成了一种新的复合物。通过SPR分析获得了关于这种相互作用的结合亲和力。结果表明，红花苷可以与HSA以K = 8.726×10M的结合亲和力形成1:1复合物，并且高温不利于这种相互作用。ITC分析和分子对接结果表明，HSA形成了一个合适的腔（位点I）来嵌入整个红花苷分子，并且复合物是通过包括疏水相互作用、氢键和静电力在内的分子间力形成的。此外，圆二色性和三维荧光表明，红花苷略微干扰了氨基酸残基的微环境并影响了HSA的二级结构。
