光谱法研究哈巴俄苷与人血清白蛋白的结合反应

发布时间：2018-03-22 19:12

  本文选题：玄参　切入点：哈巴俄苷　出处：《分析化学》2017年05期 　论文类型：期刊论文

【摘要】：在不同温度及模拟血液pH值条件下,采用荧光光谱法和紫外-可见吸收光谱法研究了哈巴俄苷(Harpagoside,HAR)与人血清白蛋白(Human serum albumin,HSA)的结合反应。结果表明,HAR有规律地使HSA内源荧光猝灭,猝灭常数随温度升高而降低,其猝灭机制为两者形成复合物而引起的的静态猝灭;不同条件下两者结合常数K_A均大于10~5L/mol,结合位点数n≈1。由Van't Hoff方程计算获得了不同条件下HAR与HSA相互作用的热力学参数,由ΔG、ΔH和ΔS均小于0可知,两者结合的主要作用力是氢键和范德华力,且两者结合是吉布斯自由能降低的自发过程。根据F銉rster非辐射转移理论计,计算了不同条件下HAR与HSA的结合距离r在4.01~4.28 nm范围内,表明两者结合过程发生了非辐射能量转移。同步荧光光谱表征结果表明,HAR使HSA的色氨酸和酪氨酸残基所处的微环境极性增强,疏水性减弱,导致HSA构象发生了一定程度的改变。
[Abstract]:Under different temperature and simulated blood pH value, the binding reaction of Harpagoside HARs with human serum albumin (HSA) was studied by fluorescence spectrometry and UV-Vis absorption spectrometry. The results showed that Har regularly quenched the endogenous fluorescence of HSA. The quenching constant decreases with the increase of temperature, and the quenching mechanism is the static quenching caused by the formation of complex between the two. Under different conditions, the binding constant K _ s _ A is greater than 10 ~ 5L / mol, and the binding site number n 鈮，

本文编号：1649996