大豆Em(LEA1)蛋白保守结构域的结构和聚集特性

摘要

In this study, we investigated the structures and assembly of C domain of soybean late embryogenesis abundant (LEAI) protein EM(Em-C) and M domain of soybean LEAI protein EM (Em-2M) from the soybean LEAI protein Em in different environments using CD and NMR spectros-copy. In water and dimyristoylphosphatidyglycerol(DMPG) solution, both peptides were predominantly disordered. In 50% 2,2,2-trifluoroethanol(TFE) aqueous solution, Em-C had increasing folding and self-assembled as dimer, and the region including hydrophobic residues might form helical structure. Em-2M formed less ordered structure than Em-C and existed as monomer in 50% TFE aqueous solution. These results suggested that the change of environment might lead to variation of spatial structure and assembly behavior for the two peptides Em-C and Em-2M. The present study may provide an insight into the structural properties of Em protein in different environments and the roles of some important segments in Em protein.%采用圆二色谱(CD)和核磁共振波谱(NMR)方法研究了大豆Em(LEA1)蛋白保守基序Em-C和Em-2M多肽在不同环境中的结构及聚集行为.研究表明,在水和DMPG溶液中,两种多肽主要以无规结构形式存在.在50％ TFE溶液中,Em-C多肽折叠结构增加,含疏水残基的部分区域可能形成α-螺旋结构,且分子以二聚体形式存在；而Em-2M则以单体形式存在,且有序结构较少.以上结果表明,环境变化可能导致两种多肽的空间结构和聚集行为改变,这有助于理解Em蛋白在不同环境中的结构特点,及其重要区域在全长蛋白中所起的作用.