新的植物毒素蒜头果蛋白的荧光光谱研究  

Fluorescence Spectra Study of a New Toxic Protein from Malania Oleifera

作　　者：袁燕[1,2] 肖涵[1] 康洪钧[1] 陈睿彦[1] 戴晓畅[1] 

机构地区：[1]云南大学化学科学与工程学院教育部自然资源药物化学重点实验室,云南昆明650091 [2]昆明学院生命科学与技术系,云南昆明650031

出　　处：《光谱学与光谱分析》2009年第3期777-780,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(30360025);云南省教育厅基金项目(07Y40677);昆明学院校级课题项目(z2008-008)资助

摘　　要：蒜头果蛋白(Malanin)是从我国稀有植物蒜头果中分离纯化出的一种具有高细胞毒性的蛋白质。用荧光光谱法研究在温度、酸度、有机溶剂、表面活性剂、变性剂及荧光猝灭剂等不同条件对蒜头果蛋白溶液构象的变化。实验表明,Malanin在天然状态下荧光发射峰位于340 nm处,色氨酸(Trp)残基较大程度位于Malanin分子的疏水区。十二烷基硫酸钠、异硫氰酸胍、丙烯酰胺和碘化钾的加入均可使Malanin的分子构象发生变化,导致分子内Trp残基的荧光猝灭。异硫氰酸胍的加入使Trp残基的荧光发射峰位明显红移,表明位于Malanin分子较疏水环境内的Trp残基相对外露。A new toxic protein named malanin was isolated from seeds of Malania oleifera by hydrophobic chromatography, whose cytotoxic activities against carcinoma cells were very strong. The conformational changes of malanin at various temperatures, pH, organic solvents, surfactant, denaturant and fluorescence quenching solvents were studied by fluorescence spectra. The fluorescence spectra of malanin excited at 280 nm and 295 nm showed a maximum at 340 nm. The emission spectra of malanin showed that Trp residues were located by a great degree in the hydrophohic area. Addition of SDS, CH5N3· HSCN, acrylamide and KI led to changes in the molecular conformation of malanin, and caused the fluorescence quenching of Trp residues. The red-shifted emission hand of malanin after adding CH5 N3 · HSCN showed that Trp residues were exposed in polar solvents.

关 键 词：蒜头果蛋白 荧光光谱 蛋白质构象 

分 类 号：O629.7[理学—有机化学]