绿色木霉纤维二糖水解酶Ⅱ的X射线辐射损伤研究  

Damage Analyse of X-Ray Radiated Cellobiohydrolase Ⅱ Molecule from Trichoderma Viride

作　　者：余多慰[1] 袁生[1] 

机构地区：[1]南京师范大学生命科学学院,江苏南京210097

出　　处：《光谱学与光谱分析》2007年第4期819-822,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学研究基金项目(30170005);江苏省高校自然科学研究基金项目(03KJB180064)资助

摘　　要：南京师范大学生命科学学院,江苏南京210097摘要根据半胱氨酸相关的拉曼光谱分析指标,采用X光管1.82keV,40mA,处理4h的辐射条件,水溶液中绿色木霉纤维二糖水解酶Ⅱ的各种S—H伸缩振动拉曼谱带虽然偏移不多,但呈现了二极分化的演变状态。辐照后的样品中2554cm-1峰宽加大。辐照没有引起维系高级空间结构存在的二硫键断裂,二硫键键长有缩小变化,二硫键几何构象类型未改变,但各种异构体成分的相对含量有变化,辐射前半胱氨酸C—S键异构体特征模PC型略多,辐射后PN和PH型增多。除半胱氨酸CH2摇摆的贡献在辐射后有明显减弱外,此辐射条件没有造成拉曼技术所能证明的与巯基有关的蛋白结构的明显损伤,但可见有变化存在。After X-ray treatment at 1.82 keV and 40 mA and 4 hours, the cellobiohydrolase Ⅱ （CBH Ⅱ） aqueous solution of Trichoderma viride was analysed, and the damage state of the irradiated molecule was detected using some cysteine residue relative parameters in Raman spectroscopic methods. The results show that S-H stretch modes of CBH Ⅱ exhibited some shift, which means that the hydrogen proton donor state of sulfbydryl groups was stronger and weaker, respectively. The 2 554 cm^- 1 peak of irradiated sample was wide. The -S -S- construction of disulfide bonds was not broken, and the geometrical conformation types did not change either, but its bond length was somewhat shortened. Before irradiation, C-S isomer mode content of cysteine residue was Pc type slightly more than both PN and P. types, while PN and P. types increased after irradiation. Besides, CH2 rocking mode of cysteine residue was weakened remarkably after the treatement, and the protein molecule structure did not show important damage in sulfhydryl and disulfide bonds, but showed some change because of the X-ray irradiation condition.

关 键 词：辐射 纤维二糖水解酶Ⅱ 半胱氨酸 拉曼光谱 

分 类 号：O657.3[理学—分析化学]