Zhang Yuran, Dee Derek R
Food, Nutrition and Health, Faculty of Land and Food Systems, The University of British Columbia, 2205 East Mall, Vancouver, British Columbia V6T 1Z4, Canada.
J Agric Food Chem. 2023 Mar 22;71(11):4755-4765. doi: 10.1021/acs.jafc.2c08704. Epub 2023 Mar 8.
Legume seed storage proteins can be induced to form amyloid fibrils upon heating at low pH, which could improve their functionality for use in food and materials. However, the amyloidogenic regions of legume proteins are largely unknown. Here, we used LC-MS/MS to determine the amyloid core regions of fibrils formed by enriched pea and soy 7S and 11S globulins at pH 2, 80 °C, and characterized their hydrolysis, assembly kinetics, and morphology. A lag phase was absent from the fibrillation kinetics of pea and soy 7S globulins, while 11S globulins and crude extracts displayed a similar lag time. Pea and soy protein fibrils differed in morphology, with most pea fibrils being straight and soy fibrils being worm-like. Pea and soy globulins were abundant in amyloid-forming peptides, with over 100 unique fibril-core peptides from pea 7S and around 50 unique fibril-core peptides identified from pea 11S, soy 7S, and soy 11S globulins. Amyloidogenic regions derive predominantly from the homologous core region of 7S globulins and the basic subunit of 11S globulins. Overall, pea and soy 7S and 11S globulins are rich in amyloidogenic regions. This study will help understand their fibrillation mechanism and engineer protein fibrils with specific structures and functionality.
豆类种子储存蛋白在低pH值下加热时可被诱导形成淀粉样纤维，这可能会改善它们在食品和材料中的功能。然而，豆类蛋白的淀粉样生成区域在很大程度上尚不清楚。在这里，我们使用液相色谱-串联质谱法（LC-MS/MS）来确定富集的豌豆和大豆7S和11S球蛋白在pH 2、80°C条件下形成的纤维的淀粉样核心区域，并对它们的水解、组装动力学和形态进行了表征。豌豆和大豆7S球蛋白的纤维化动力学没有延迟期，而11S球蛋白和粗提物表现出相似的延迟时间。豌豆和大豆蛋白纤维在形态上有所不同，大多数豌豆纤维是直的，而大豆纤维是蠕虫状的。豌豆和大豆球蛋白富含形成淀粉样的肽段，从豌豆7S中鉴定出100多个独特的纤维核心肽段，从豌豆11S、大豆7S和大豆11S球蛋白中鉴定出约50个独特的纤维核心肽段。淀粉样生成区域主要源自7S球蛋白的同源核心区域和11S球蛋白的碱性亚基。总体而言，豌豆和大豆7S和11S球蛋白富含淀粉样生成区域。这项研究将有助于理解它们的纤维化机制，并设计具有特定结构和功能的蛋白质纤维。
