Department of Nutrition, Food and Exercise Sciences, College of Human Sciences, The Florida State University, Tallahassee, Florida 32306-1493, USA.
J Agric Food Chem. 2010 May 12;58(9):5714-23. doi: 10.1021/jf9036326.
Brazil nut storage proteins, 2S albumin, 7S vicilin, and an 11S legumin, were purified using column chromatography. Analytical ultracentrifugation of the purified albumin, vicilin, and legumin proteins, respectively, registered sedimentation coefficients of 1.8, 7.1, and 11.8 S. Under reducing conditions, the major polypeptide bands in 2S albumin were observed at 6.4, 10-11, and 15.2 kDa. The 7S globulin was composed of one 12.6 kDa, two approximately 38-42 kDa, and two approximately 54-57 kDa polypeptides, whereas the 11S globulin contained two major classes of polypeptides: approximately 30-32 and approximately 20-21 kDa. The 7S globulin stained positive when reacted with Schiff reagent, indicating that it is a glycoprotein. The estimated molecular mass and Stokes radius for 2S albumin and 7S and 11S globulins were 19.2 kDa and 20.1 A, 114.8 kDa and 41.1 A, and 289.4 kDa and 56.6 A, respectively. Circular dichroism spectroscopic analysis indicated the secondary structure of the three proteins to be mainly beta-sheets and turns. Emission fluorescence spectra of the native proteins registered a lambda(max) at 337, 345, and 328 nm for 2S albumin and 7S and 11S globulins, respectively. When probed with anti-Brazil nut seed protein rabbit polyclonal antibodies, 7S globulin exhibited higher immunoreactivity than 2S albumin and 11S globulin.
巴西坚果贮藏蛋白 2S 白蛋白、7S 菜豆球蛋白和 11S 豆球蛋白经柱层析法纯化。经分析超速离心分别得到纯化的白蛋白、菜豆球蛋白和豆球蛋白的沉降系数为 1.8、7.1 和 11.8S。在还原条件下，2S 白蛋白中主要的多肽带在 6.4、10-11 和 15.2 kDa 处观察到。7S 球蛋白由一个 12.6 kDa、两个约 38-42 kDa 和两个约 54-57 kDa 的多肽组成，而 11S 球蛋白包含两类主要的多肽：约 30-32 kDa 和约 20-21 kDa。7S 球蛋白与 Schiff 试剂反应呈阳性，表明它是一种糖蛋白。2S 白蛋白和 7S 和 11S 球蛋白的估计分子量和 Stokes 半径分别为 19.2 kDa 和 20.1 A、114.8 kDa 和 41.1 A、289.4 kDa 和 56.6 A。圆二色光谱分析表明，三种蛋白质的二级结构主要为β-折叠和转角。天然蛋白质的发射荧光光谱分别在 337、345 和 328 nm 处记录到 2S 白蛋白和 7S 和 11S 球蛋白的 lambda(max)。用抗巴西坚果种子蛋白兔多克隆抗体探测时，7S 球蛋白的免疫反应性高于 2S 白蛋白和 11S 球蛋白。
