Food Colour & Quality Lab., Área de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain.
Grupo de Investigación en Polifenoles, Facultad de Farmacia, Universidad de Salamanca, Campus Miguel de Unamuno, E 37007 Salamanca, Spain.
Food Chem. 2023 Jul 1;413:135591. doi: 10.1016/j.foodchem.2023.135591. Epub 2023 Jan 31.
Recently, the search for alternative proteins endogenous to grapes to be used as wine colour protecting agents became an important research trend. In this study, the molecular interaction between the grape seed 11S globulin from winemaking by-product and malvidin-3-O-glucoside was investigated by fluorescence, differential colorimetry and molecular modelling. Fluorescence studies revealed the formation of grape seed protein- pigment complex whose K was 8.5 × 10 M and binding sites, n = 1.3. Malvidin-3-O-glucoside showed darker and more vivid bluish colour of in the presence of 11S globulin, suggesting the flavylium cation protection in a hydrophobic region of the protein. Docking analysis and molecular dynamics simulation indicated that malvidin-3-O-glucoside interacts mainly with the acidic subunit (40 kDa) of the 11S globulin monomer (60 kDa). An average of two hydrogen bonds and Van der Wall forces were the main interaction forces found for the protein-pigment complex, whose stability was confirmed by root-means-square deviation.
最近，人们一直在寻找替代葡萄中原有的蛋白质，以作为葡萄酒颜色保护剂，这已成为一个重要的研究趋势。本研究通过荧光、差示比色法和分子建模研究了葡萄酒副产物中葡萄籽 11S 球蛋白与矢车菊素-3-O-葡萄糖苷之间的分子相互作用。荧光研究表明，形成了葡萄籽蛋白-色素复合物，其 K 值为 8.5×10 M，结合位点数 n=1.3。在 11S 球蛋白存在的情况下，矢车菊素-3-O-葡萄糖苷显示出更深、更生动的蓝色，表明花色素阳离子在蛋白质的疏水区域得到保护。对接分析和分子动力学模拟表明，矢车菊素-3-O-葡萄糖苷主要与 11S 球蛋白单体（60 kDa）的酸性亚基（40 kDa）相互作用。对于蛋白质-色素复合物，氢键和范德华力的平均值是主要的相互作用力，其稳定性通过均方根偏差得到证实。
