Li Yu, Qiao Yuqian, Zhu Yuxuan, Shen Wangyang, Jin Weiping, Peng Dengfeng, Huang Qingrong
School of Food Science and Engineering, Wuhan Polytechnic University, Wuhan, Hubei 430023, PR China.
Key Laboratory of Oilseeds Processing, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, PR China.
Food Chem X. 2024 Nov 20;25:102022. doi: 10.1016/j.fochx.2024.102022. eCollection 2025 Jan.
During the extraction of membrane proteins from oil bodies (OBs), organic solvents dissolve the lipid core and precipitate proteins through solvent stress. Here the effects of solvent type and defatting sequence on the composition and structure of membrane proteins were investigated SDS-PAGE, FTIR, and SEM-EDS. High purity oleosin (86 %) was obtained by treatment first with a Floch solution and then with cold acetone and petroleum ether after twice washing OBs with urea. The 3D spatial structure of oleosin was predicted using AlphaFold 2, revealing that the secondary structure of oleosin was dominated by α-helices (>60 %). Oleosin consisted of two district types, with oleosin-H (16-17 kDa) being the part of the molecule with limited water solubility, while oleosin-L (13-14 kDa) constituted the non-soluble part. The results provided a technical means of efficient extraction of oleosins and selective separation of oleosin-L and oleosin-H.
在从油体（OBs）中提取膜蛋白的过程中，有机溶剂溶解脂质核心并通过溶剂胁迫使蛋白质沉淀。在此，利用SDS-PAGE、FTIR和SEM-EDS研究了溶剂类型和脱脂顺序对膜蛋白组成和结构的影响。在用尿素洗涤OBs两次后，先用Floch溶液处理，然后用冷丙酮和石油醚处理，获得了高纯度油质蛋白（86%）。使用AlphaFold 2预测了油质蛋白的三维空间结构，结果表明油质蛋白的二级结构以α-螺旋为主（>60%）。油质蛋白由两种不同类型组成，其中油质蛋白-H（16 - 17 kDa）是分子中水溶性有限的部分，而油质蛋白-L（13 - 14 kDa）构成不溶性部分。该结果为高效提取油质蛋白以及选择性分离油质蛋白-L和油质蛋白-H提供了一种技术手段。
