芦丁与溶菌酶相互作用的光谱研究

Spectroscopic Studies on the Interaction of Rutin and Lysozyme

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。

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).