通过反胶束和碱提取与等电沉淀获得的核桃蛋白级分的结构比较。

Comparison of structures of walnut protein fractions obtained through reverse micelles and alkaline extraction with isoelectric precipitation.

机构信息

Department of Food Science and Nutrition, Culinary Institute, University of Jinan, Jinan 250022, China.

出版信息

Int J Biol Macromol. 2019 Mar 15;125:1214-1220. doi: 10.1016/j.ijbiomac.2018.09.095. Epub 2018 Sep 17.

DOI:10.1016/j.ijbiomac.2018.09.095

Abstract

The effects of different extraction methods on the contents of disulfide (SS) and sulfhydryl (SH) and secondary structure of albumin, globulin, prolamin and glutelin fractions from walnut proteins were evaluated. By comparison with the changing trend for four protein fractions from alkali extraction with isoelectric precipitation (AEIP), the SH contents of globulin, prolamin and glutelin fractions from the reverse micelles (RMs) significantly increased (p < 0.05), but decreased in the albumin faction. The SS bond contents of albumin, globulin and glutelin fractions obtained by two extraction methods were similar, except that the SS bond content in prolamin obtained through RMs increased by 2.57%. Fourier transform infrared (FTIR) results showed that the proportions of α-helix in globulin, β-sheet structure in prolamin, unordered structure in globulin, prolamin and glutein, turn structure in albumin, prolamin and glutelin by RMs were higher than those by AEIP. Scanning electron microscopy showed that the reverse micelle extraction could affect the surface structures of four protein fractions.

摘要

评价了不同提取方法对核桃蛋白中二硫键（SS）和巯基（SH）含量及白蛋白、球蛋白、醇溶蛋白和谷蛋白各组分二级结构的影响。与碱提等电沉淀（AEIP）的 4 种蛋白组分的变化趋势相比，反胶束（RMs）提取的球蛋白、醇溶蛋白和谷蛋白巯基含量显著增加（p < 0.05），而白蛋白巯基含量降低。两种提取方法得到的白蛋白、球蛋白和谷蛋白的 SS 键含量相似，除了通过 RMs 得到的醇溶蛋白的 SS 键含量增加了 2.57%。傅里叶变换红外（FTIR）结果表明，RMs 提取的球蛋白中的α-螺旋、醇溶蛋白中的β-折叠结构、球蛋白、醇溶蛋白和谷蛋白中的无规卷曲结构、白蛋白、醇溶蛋白和谷蛋白中的转角结构的比例均高于 AEIP 提取的相应结构。扫描电子显微镜表明，反胶束提取可以影响 4 种蛋白组分的表面结构。