大豆7S和11S蛋白二级结构与表面疏水性相关性的研究

Correlation of Secondary Structures of 7S and 11S Soybean Proteins and Their Surface Hydrophobicity

以6个具有代表性的大豆品种作为实验材料提取7S和11S蛋白,并经Superdex 200凝胶柱层析进行纯化,采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳验证其纯度均在90%以上。采用傅里叶红外光谱分析7S和11S蛋白的二级结构,采用ANS荧光探针法测定7S和11S蛋白的表面疏水性,利用相关性分析探讨7S和11S蛋白表面疏水性与二级结构的构效关系。经分析得出:大豆蛋白的表面疏水性与α-螺旋含量成负相关;与β-折叠含量成负相关;与β-转角含量成正相关,与无规卷曲含量成正相关。

7S and 11S proteins were extracted from six representative soybean varieties, and purified with Superdex 200 gel column chromatography to a purity more than 90% as determined by using sodium dodecyl sulfate polyacrylamide gel electrophoresis （SDS-PAGE）. The secondary structures of 7S and 1IS proteins were analyzed with Fourier transform infrared spectroscopy. The surface hydrophobicities of 7S and 11S proteins were determined with 1-anilinonaphthalene-8- sulfonic acid （ANS） fluorescence probe method. The structure-activity relationship was discussed with correlation analysis. It was concluded that the surface hydrophobicity of the soybean proteins was negatively related to alpha helix content and beta folding content but was positively correlated with beta angle content and random curl content.