摘要
在模拟人体生理条件下,采用紫外光谱、荧光光谱和同步荧光光谱法相结合,研究槐果碱(SC)和氧化槐果碱(OSC)与溶菌酶(LYSO)的相互作用机制,并探讨其构效关系。紫外光谱显示,SC和OSC可与LYSO发生相互作用;荧光光谱表明,SC和OSC对LYSO的内源荧光均有显著的猝灭作用,猝灭机制主要为静态猝灭和非辐射能量转移。SC和OSC均可与LYSO形成1∶1复合物,在温度为310K下二者与LYSO的结合常数K分别为0.922×105、2.81×105 L·mol-1,结合距离r分别为3.81、4.39nm,其作用力主要为氢键和范德华力。OSC与LYSO的结合能力明显强于SC;同步荧光光谱表明,OSC与LYSO相互作用后,LYSO的构象发生改变,而SC与LYSO相互作用后,LYSO的构象基本不变。Fe3+、Mg2+、Cu2+、Zn2+四种金属离子的存在增强了SC和OSC与LYSO的结合能力,四种金属离子均以"离子架桥"模式介导SC和OSC与LYSO的相互作用,且其强弱顺序为:Mg2+>Cu2+>Fe3+>Zn2+。
The interaction mechanism and structure-activity relationship of lysozyme（LYSO）with sophocarpine（SC）and oxysophocarpine（OSC）were investigated by ultraviolet spectroscopy,fluorescence spectroscopy and synchronous fluorescence spectroscopy under the simulative human physiological conditions.The result of ultraviolet difference spectra initially revealed that SC and OSC could interact with LYSO.Fluorescence spectra showed that the intrinsic fluorescence of LYSO had been significantly quenched by SC and OSC via static quenching with non-radiation energy transfer.The 1∶1complex was formed between SC/OSC and lysozyme,the binding constants（K）were 0.922×10^5 and 2.81×10^5 L·mol^-1,and the binding distance（r）were 3.81 and 4.39 nm,respectively.The combining ability of OSC with LYSO was stronger than that of SC with LYSO.The results of synchronous fluorescence spectrum showed that the conformation of LYSO was changed by OSC,while the conformation of LYSO basically remained unchanged by SC.Four kinds of metal ions such as Fe^3＋enhanced the combinational ability of SC and OSC with LYSO by means of ＂ionic bridge＂ interaction and their order was as follows：Mg^2＋〉Cu^2＋〉Fe^3＋〉Zn^2＋.
出处
《分析科学学报》
CAS
CSCD
北大核心
2014年第6期885-889,共5页
Journal of Analytical Science
基金
山西省自然科学基金(No.2010011048-1)
山西医科大学科技创新基金(01200806)
太原市2012年科学技术发展计划大学生创新创业项目(120164073)
关键词
槐果碱
氧化槐果碱
溶菌酶
光谱法
荧光猝灭机制
构效关系
Sophocarpine
Oxysophocarpine
Lysozyme
Spectroscopy
Mechanism of fluorescence quenching
Structure-activity relationship
