脲对含内蛋白子前体蛋白剪切的影响  

Effect of Urea on Splicing of a Precursor

作　　者：范俊虎[1] 石亚伟 袁静明[1] 

机构地区：[1]山西大学生物工程实验室

出　　处：《山西大学学报（自然科学版）》1998年第3期252-256,共5页Journal of Shanxi University(Natural Science Edition)

基　　金：国家自然科学基金

摘　　要：研究了含内蛋白子的前体蛋白［麦芽糖结合蛋白－内蛋白子－几丁质酶结合区（ＭＹＢ）］在脲溶液中的分子构象及变性和复性过程中剪切活性与光谱变化的关系。结果表明，剪切活性随脲浓度的增加而逐渐丧失；当脲浓度大于６ｍｏｌ／Ｌ时，活性完全丧失。变性过程中Ａ２８０ｎｍ随变性程度增加而增强，复性后Ａ２８０ｎｍ与天然态Ａ２８０ｎｍ值相近，剪切活性随之恢复。说明构象松散先于剪切活性，可能在重折叠时，构象核化对剪切活性致关重要。The relationship between conformational changes and splicing activity of a precursor MYB(maltose binding protein-yeast intein-chitinase binding domain)in the presence of urea was studied by UV-spectra and SDS-PAGE.The results showed that the splicing activity was completely lost at 6mol/L urea to follow the rapid increase of UV absorption at A280nm. If the precursor denaturated was dialyzed with Tris-HCL buffer for 24h at RT., not only the splicing activity of the renaturated protein was basically all recovered,but also the A280nm absorption was lowed to the level of natural precursor.Compared with the changes of splicing activity and A280nm absorption,it is indicated that the conformational unfolding for the precursor is faster than the loss of splicing activity.

关 键 词：前体蛋白 内蛋白子 脲 剪切 变性 复性 

分 类 号：Q51[生物学—生物化学]