荧光光谱法和分子模拟技术研究考马斯亮蓝G-250与牛血清白蛋白的相互作用

发布时间：2018-06-09 23:35

  本文选题：光谱法 + 分子模拟　； 参考：《光谱学与光谱分析》2017年08期

【摘要】：采用多种光谱技术结合圆二色谱技术研究了考马斯亮蓝G-250(CBBG-250)相互作用于牛血清白蛋白(BSA),探究了两者之间的作用机理。荧光光谱结果表明BSA与CBBG-250结合形式是静态猝灭,随CBBG-250浓度增加,其形成常数随温度逐渐减小,结合比为1∶1,根据Stern-Volmer曲线计算焓变值(ΔH)和熵变值(ΔS)分别为-4.38kJ·mol~(-1)和-6.16J·mol~(-1)·K~(-1),均小于零,证明该过程是一个自发过程。傅里叶红外光谱测定结果表明CBBG-250的加入引起BSA结构的变化,随着CBBG-250溶液浓度的增加,BSA中色氨酸微环境极性被改变,在1 600~1 700cm~(-1)(酰胺带Ⅰ)和1 600~1 500cm~(-1)(酰胺带Ⅱ)处的特征吸收带蓝移。其中1 650cm~(-1)移动至1 710cm~(-1),1 544cm~(-1)移动到1 573cm~(-1),显示BSAα-螺旋(1 650~1 658cm~(-1))和β-折叠(1 620~1 640cm~(-1),1 675cm~(-1))结构发生变化,且α-螺旋含量比结合前有所降低。圆二色谱分析结果表明,两者间通过氢键和范德华力为主的作用力使得BSA二级结构发生变化,α-螺旋含量由42.15%下降至1.27%,该结果进一步被分子建模对接技术证明。
[Abstract]:The interaction between Coomassie brilliant blue G-250 (CBBG-250) and bovine serum albumin (BSA) was studied by means of multiple spectral techniques and circular dichroism. The fluorescence spectra show that the binding form of BSA and CBBG-250 is static quenching. With the increase of CBBG-250 concentration, the formation constant decreases gradually with the temperature and the binding ratio is 1: 1. The calculated values of enthalpy variation (螖 H) and entropy variation (螖 S) based on Stern-Volmer curve are -4.38 kJ / mol ~ (-1) and -6.16 J / mol ~ (-1) K ~ (-1), respectively, which are less than zero. It is proved that this process is a spontaneous process. The results of Fourier transform infrared spectroscopy showed that the addition of CBBG-250 caused the change of BSA structure, and the microenvironmental polarity of tryptophan in BSA changed with the increase of CBBG-250 solution concentration. The blue shift of the absorption band is observed at 1 600 ~ 1 700 cm ~ (-1) (amide band 鈪，

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