Di Dakai, Zhang Rong, Li Huimei, Qiu Min, Jiang Suwei, Luo Shuizhong, Sun Hanju, He Shudong
School of Food and Biological Engineering, Engineering Research Center of Bio-process of Ministry of Education, Anhui Province Key Laboratory of Agricultural Products Modern Processing, Hefei University of Technology, Hefei 230009, Anhui, PR China.
School of Biology, Food and Environment, Hefei University, 230601, Hefei, Anhui, PR China.
Food Chem. 2025 Jul 30;481:144095. doi: 10.1016/j.foodchem.2025.144095. Epub 2025 Mar 29.
A systematic extraction protocol involving multiple oil body washing with buffers of NaHCO₃ (pH 10), NaCl, and urea was investigated, and the enrichment of α-helix-rich hydrophobic proteins were monitored by the spectroscopic techniques, while the isolated proteins were identified as oleosin with a relative content of 81.05 %. Dot-blot analysis revealed the allergenicity was enhanced at 150 °C compared to the unroasted state, followed by a decline at 180 °C. SDS-PAGE and size exclusion chromatography showed the formation of higher molecular weight aggregates during roasting, while spectroscopy methods indicated a complex process of protein unfolding, folding, and re-unfolding, along with secondary structure modifications. Molecular dynamics simulations indicated structural alterations and flexibility changes, especially at the N- and C-terminal domains of oleosins, within the phospholipid membrane. Protein-protein docking demonstrated the strong self-association of oleosins after roasting. This study offers theoretical reference for deeper understanding of the structural alterations of sesame oleosins post-roasting.
研究了一种系统提取方案，该方案涉及用NaHCO₃（pH 10）、NaCl和尿素缓冲液多次洗涤油体，并用光谱技术监测富含α-螺旋的疏水蛋白的富集情况，同时鉴定出分离出的蛋白为油质蛋白，其相对含量为81.05%。斑点印迹分析表明，与未烘焙状态相比，在150℃时致敏性增强，随后在180℃时下降。SDS-PAGE和尺寸排阻色谱显示烘焙过程中形成了更高分子量的聚集体，而光谱方法表明了蛋白质展开、折叠和重新展开的复杂过程以及二级结构修饰。分子动力学模拟表明，在磷脂膜内，油质蛋白的结构发生了改变，灵活性发生了变化，尤其是在油质蛋白的N端和C端结构域。蛋白质-蛋白质对接表明烘焙后油质蛋白有很强的自缔合作用。本研究为深入了解芝麻油质蛋白烘焙后的结构变化提供了理论参考。
