食品科学2018，Vol.39Issue(12)：33-39,7.DOI:10.7506/spkx1002-6630-201812006
大豆分离蛋白与花青素非共价及共价作用对蛋白构象变化的影响
Analysis of Non-Covalent and Covalent Interactions between Anthocyanins and Soybean Protein Isolate on Protein Conformational Change
摘要
Abstract
In this paper, non-covalent binding (pH 7.4, 2 h) and covalent cross-linking (pH 9, 24 h) were used to analyze the variations of protein conformations in soybean protein isolate (SPI)-anthocyanins complexes. The changes in protein structure in the composite systems were studied by turbidity measurement, binding capacity, gel electrophoresis analysis, fluorescence spectroscopy and infrared spectroscopy. The results of gel electrophoresis showed the formation of macromolecular derivatives in complexes 4, 5 and 6 (SPI/anthocyanins ratio = 20:1, 10:1, 5:1, m/m) by covalent cross-linking. The turbidity values of the covalently cross-linked complexes were lower than that of the non-covalently bound ones (1, 2 and 3), and the affinity of the anthocyanins in the covalently cross-linked complexes were stronger. The fluorescence intensity of the proteins was decreased with the increase of anthocyanins in complexes and tryptophan residues were exposed to a more hydrophilic environment. This finding suggested that the fluorescence quenching effect of the covalently cross-linked complexes were obvious. Covalent cross-linking was greater than non-covalent binding; the infrared absorption intensities of the proteins in complexes 1 and 4 were significantly decreased, indicating that the secondary structure of the proteins is changed. In addition, the contents of β-turn and irregular structure in sample 4 were higher, indicating that the covalent cross-linking mechanism of anthocyanins in the complex reveals a stronger ability to unfold the proteins.关键词
大豆分离蛋白/花青素/非共价作用/共价作用/构象变化Key words
soybean protein isolate/anthocyanins/non-covalent interactions/covalent interactions/conformational change分类
轻工纺织引用本文复制引用
孙红波,李杨,王立敏,董济萱,隋晓楠,齐宝坤,王中江,江连洲..大豆分离蛋白与花青素非共价及共价作用对蛋白构象变化的影响[J].食品科学,2018,39(12):33-39,7.基金项目
国家自然科学基金青年科学基金项目(31601475) （31601475）
国家自然科学基金面上项目(31671807) （31671807）
"十三五"国家重点研发计划重点专项(2016YFD0401402 （）
2016YFD0400700) （）
