嵌合蛛丝蛋白Flag-MaSp1重复模块的表达及二级结构分析  

Expression and Secondary Structure Analysis of Chimeric Spidroin from Flag-MaSp1 Repetitive Modules

作　　者：田露阳 孟清[1] 林瑛[1] TIAN Lu-yang;MENG Qing;LIN Ying(College of Chemistry,Chemical Engineering and Biotechnology,Donghua University,Shanghai 201620,China)

机构地区：[1]东华大学化学化工与生物工程学院,中国上海201620

出　　处：《生命科学研究》2020年第5期396-403,共8页Life Science Research

基　　金：上海市科学技术委员会自然科学基金资助项目(19ZR1471000);国家自然科学基金委面上项目(31470836)。

摘　　要：蜘蛛能够产生7种具有不同机械性能的丝纤维及胶状物质。其中,鞭状腺丝(flagelliform silk)具有最好的弹性,拖丝(dragline silk)具有最高的强度。本文将来源于大腹园蛛(Araneus ventricosus)鞭状腺丝蛋白(flagelliform spidroin,Flag)的一个重复模块与组成拖丝的蛋白质之一的主壶腹腺丝蛋白1(major ampullate spidroin,MaSp1)的一个重复模块相融合。经原核表达得到的嵌合蛛丝蛋白FlagR-MaSp1R在施加剪切力的作用下可自组装形成丝状纤维。圆二色谱分析显示,在pH 7.0溶液中,FlagR-MaSp1R蛋白的二级结构以α-螺旋为主;傅里叶变换红外光谱分析结果表明,FlagR-MaSp1R形成丝纤维时二级结构由α-螺旋向β-折叠转变;扫描电镜观察结果显示,嵌合丝纤维表面光滑,直径为1~2μm,接近天然丝纤维。上述结果为制备特定功能的嵌合蛛丝纤维提供了理论基础及方法支持。Spiders can produce seven different types of silks or glues with different mechanical properties.Among them,flagelliform silk has the best elasticity,and dragline silk has the highest strength.Herein,one repetitive module of flagelliform spidroin(Flag)and one repetitive module of major ampullate spidroin(MaSp1)from Araneus ventricosus were fused.The chimeric spidroin FlagR-MaSp1R expressed by E.coli can be selfassembled to silk-like fibers by shear force.Further circular dichroism(CD)spectrum analysis showed that the secondary structure of FlagR-MaSp1R protein in solution was dominated by α-helix at pH 7.0.However,in the process of fiber-forming,the secondary structure of FlagR-MaSp1R was changed fromα-helix toβ-sheet as indicated by Fourier transform infrared spectroscopy(FTIR).Observation under scanning electron microscope(SEM)revealed that the chimeric silk fiber has smooth surface,and its diameter was 1~2μm,which was similar to that of natural silks.The results provide theoretical basis and method support for the preparation of chimeric spider silk fibers with specific functions.

关 键 词：嵌合蛛丝蛋白 鞭状腺丝蛋白(Flag) 主壶腹腺丝蛋白1(MaSp1) 重复模块 二级结构 

分 类 号：Q71[生物学—分子生物学]