牡荆苷与溶菌酶相互作用的荧光光谱学研究

Fluorescence spectroscopy of interactions between vitexin and lysozyme

目的在模拟人体生理条件下,研究牡荆苷与溶菌酶的相互作用的光谱学特征。方法利用同步荧光光谱法和荧光光谱法研究牡荆苷与溶菌酶的相互作用机制、作用力类型,考察牡荆苷对溶菌酶构象的影响。结果牡荆苷对溶菌酶的荧光猝灭机制为静态猝灭,牡荆苷与溶菌酶的结合常数、结合位点数分别为6.73×10~5 L/mol、1.12,其作用力以疏水作用为主。同步荧光光谱法测定的结合位点靠近色氨酸,并使色氨酸的疏水性增强。结论牡荆苷与溶菌酶结合并改变溶菌酶的构象,共存金属离子对牡荆苷与溶菌酶的相互作用有一定的影响。

Objective To study the spectroscopic characteristics of interaction between vitexin and lysozyme under the simulative human physiological condition. Methods Interaction mechanism and interaction force of vitexin with lysozyme were investigated by fluorescence spectroscopy and synchronous fluorescence spectroscopy. The effects of their interaction on conformation change of lysozyme were investigated. Results The fluorescence quenching mechanism of vitexin with lysozyme was static quenching. The binding parameters of vitexin and lysozyme were as following： The binding constant（K） was 6.73 × 10~5 L/mol, and the number of binding site was 1.12, respectively. And the major driving force was hydrophobic force. The results of synchronous fluorescence demonstrated that the binding site was closer to tryptophan residues and the hydrophobicity of tryptophan residues was increased. Conclusion Vitexin with lysozyme can form complex and change the conformation of lysozyme. The common metal ions have effects on interaction between vitexin and lysozyme.