碱性条件下大豆11S球蛋白溶液的性质和分子结构  

Solution Properties and Molecular Structure of 11S Glycinin at Alkaline Condition

作　　者：朱建宇[1] 赵城彬[2] 江连洲[1] 谢凤英[1] Zhu Jianyu;Zhao Chengbin;Jiang Lianzhou;Xie Fengying(College of Food Science,Northeast Agricultural University,Harbin 150030;College of Food Science and Engineering,Jilin Agricultural University,Changchun 130118)

机构地区：[1]东北农业大学食品学院,哈尔滨150030 [2]吉林农业大学食品科学与工程学院,长春130118

出　　处：《中国食品学报》2019年第7期85-92,共8页Journal of Chinese Institute Of Food Science and Technology

基　　金：吉林省教育厅科学研究项目(JJKH20180654KJ)

摘　　要：对碱性条件下大豆11S球蛋白溶解性、表面疏水性(H0)、Zeta电位、粒径以及分子结构进行研究。当pH值由7.0增加到12.0时,大豆11S球蛋白的溶解性增加,H0降低,Zeta电位的绝对值增大,平均粒径降低,这表明碱性条件下大豆球蛋白表面负电荷增多,通过静电排斥作用减少了蛋白质聚集,促进蛋白质溶解,更多的极性氨基酸暴露于蛋白质表面可能会导致H0降低。此外,随着pH值的升高,α-螺旋含量增加,无规卷曲含量降低,蛋白分子中的酪氨酸和色氨酸残基趋于“包埋”态。碱性条件下大豆11S球蛋白的二硫键构型发生改变,说明可能发生蛋白质亚基的解离和聚合。Solubility, surface hydrophobicity(H0), Zeta potential, particle size and molecular structure of 11S glycinin at alkaline condition were researched. When pH increased from 7.0 to 12.0, the solubility increased, H0 was reduced, absolute value of Zeta potential enhanced and average particle size decreased, which indicated that surface negative charge of 11S glycinin at alkaline condition increased, reducing protein aggregation by electrostatic repulsion and promoting the dissolution of protein. The exposure of more polar amino acid on protein surface might lead to a drop in H0. In addition,α-helix structure increased, random coil structure decreased and tyrosine and tryptophan residues in the protein molecules tended to “embedding” state with increasing pH. The disulfide bond configuration of 11S glycinin at alkaline condition was changed, suggesting that dissociation and aggregation of protein subunits could be occurred.

关 键 词：大豆11S球蛋白 表面疏水性 溶液性质 拉曼光谱 

分 类 号：TS201.21[轻工技术与工程—食品科学]