摘要
在模拟人体生理条件下,采用紫外光谱法、荧光光谱法、同步荧光光谱法和圆二色谱法相结合研究了4种呋喃香豆素类药物与溶菌酶(LYSO)的相互作用机制,并探讨了其构效关系。紫外光谱结果初步显示,4种呋喃香豆素类药物与LYSO发生相互作用。荧光光谱结果表明,4种呋喃香豆素类药物对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。4种呋喃香豆素类药物与LYSO均形成1∶1复合物,且在310 K温度下与LYSO的结合常数K分别为1.02×104、6.95×104、7.05×104、8.60×104L.mol-1,结合距离r分别为4.36、4.75、5.25、5.89 nm,其作用力主要为氢键和范德华力。呋喃环和甲氧基位置的不同导致了4种呋喃香豆素类药物与溶菌酶的作用强弱不同,其作用力顺序为:8-甲氧基补骨脂素>5-甲氧基补骨脂素>异补骨脂素>补骨脂素。圆二色谱结果表明,4种呋喃香豆素类药物与LYSO相互作用后均对LYSO的二级结构产生不同程度的影响。补骨脂素、异补骨脂素、5-甲氧基补骨脂素和8-甲氧基补骨脂素分别使得LYSO中α-螺旋结构的含量降低了27.1%、11.5%、10.6%和0.917%。同步荧光光谱结果显示,补骨脂素、5-甲氧基补骨脂素和8-甲氧基补骨脂素与LYSO相互作用后均对LYSO的构象产生影响,而异补骨脂素则对LYSO的构象影响较小。
The interaction mechanisms and structure-activity relationships of lysozyme（LYSO） with psoralen,isopsoralen,5-methoxypsoralen and 8-methoxypsoralen were investigated by ultraviolet spectroscopy,fluorescence spectroscopy,synchronous fluorescence spectroscopy and circular dichroism spectroscopy under the simulative human physiological conditions.The results of ultraviolet difference spectra initially revealed that four furanocoumarin drugs could interact with LYSO.Fluorescence spectra showed that the intrinsic fluorescence of LYSO was significantly quenched by four furanocoumarin drugs and the mechanism of fluorescence quenching was static quenching with non-radiation energy transfer.The 1 ∶ 1 complexes were formed between each of the four furanocoumarin drugs and lysozyme.The binding parameters of four furanocoumarin drugs（psoralen,isopsoralen,5-methoxypsoralen and 8-methoxypsoralen） with LYSO at 310 K were as follows：the binding constants（K） were 1.02×104,6.95×104,7.05×104 L·mol-1 and 8.60×104 L·mol-1,and the binding distance（r） were 4.36,4.75,5.25 and 5.89 nm,respectively.The major driving forces were hydrogen bond and Van der Waals.The different positions of furan ring and methoxy led to the different interactions of four furanocoumarins drugs and lysozyme,and the order of the interaction strengths between each of four furanocoumarin drugs and lysozyme were as follows：8-methoxypsoralen5-methoxypsoralenisopsoralenpsoralen.The results of circular dichroism indicated that four furanocoumarin drugs had impacts on the secondary structure of LYSO.Psoralen,isopsoralen,5-methoxypsoralen and 8-methoxypsoralen made the content of α-helical structure of LYSO reduce by 27.1%,11.5%,10.6% and 0.917%,respectively.The results of synchronous fluorescence spectra demonstrated that psoralen,5-methoxypsoralen and 8-methoxypsoralen could combine with LYSO and had effects on the conformation of LYSO,while isopsoralen had a less effect on the conformation of LYSO than the other three furanocoumarin drugs
出处
《分析测试学报》
CAS
CSCD
北大核心
2013年第1期23-31,共9页
Journal of Instrumental Analysis
基金
山西省自然科学基金资助项目(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
呋喃香豆素类药物
溶菌酶
光谱法
荧光猝灭机制
构效关系
furanocoumarin drugs
lysozyme
spectroscopy
mechanism of fluorescence quench-ing
structure - activity relationship
