[关键词]
[摘要]
在模拟人体生理pH条件下,采用荧光光谱法和紫外-可见光谱法研究不同温度下(298 K、304 K和310 K)芦丁与溶菌酶相互作用的光谱特征,明确了芦丁对溶菌酶荧光猝灭的机理,确定了二者作用间结合位点及结合常数,测定了芦丁对溶菌酶活性的影响趋势。结果表明芦丁能与溶菌酶发生弱相互作用,该作用是由焓驱动的低温自发反应过程,芦丁通过静态猝灭机制使溶菌酶内源荧光产生猝灭。两者结合位点数接近于1,结合驱动力为氢键或范德华力,298 K时结合距离为4.02 nm。紫外吸收、同步荧光和三维荧光光谱均表明芦丁导致溶菌酶构象变得更加紧密。采用比浊法测定溶菌酶活性结果表明,芦丁可能影响溶菌酶活性位点Asp-52所处微环境极性,不利于Asp-52发挥氢键受体的催化作用,使溶菌酶溶菌活性降低。
[Key word]
[Abstract]
The interaction of rutin with lysozyme (LYZ) was studied in simulating physiological condition (pH 7.40) at 298 K, 304 K and 310 K by ultraviolet-vis (UV) absorption and fluorescence spectroscopy. The results showed that rutin quenched the endogenous fluorescence of LYZ via a static quenching procedure and the interaction between them was a spontaneous process. The number of binding sites was approximately 1. Van der Waals' forces and hydrogen bonds played major roles in stabilizing rutin-LYZ complex, and the distance between the donor and acceptor was 4.02 nm (298 K). The UV absorption, synchronous fluorescence and three-dimensional fluorescence spectra showed that the conformation of LYZ became more tightly packed. The turbidimetric analysis showed that rutin decreased LYZ activity. Rutin may be bad for the hydrogen-bonding receptor catalysis activity of Asp-52 by affecting the micro-environment of lysozyme activity site (Asp-52).
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[基金项目]
河北省自然科学基金(08B033);河北省卫生厅重点课题计划(20100241);河北省中医药管理局基金(2012011)