Ye Xinchen, Hedenqvist Mikael S, Langton Maud, Lendel Christofer
Dept. of Fibre and Polymer Technology, KTH Royal Institute of Technology Stockholm Sweden.
Dept. of Molecular Sciences, Swedish University of Agricultural Sciences Uppsala Sweden.
RSC Adv. 2018 Feb 13;8(13):6915-6924. doi: 10.1039/c7ra10981d. eCollection 2018 Feb 9.
Self-assembly of proteins into amyloid-like nanofibrils is not only a key event in several diseases, but such fibrils are also associated with intriguing biological function and constitute promising components for new biobased materials. The bovine whey protein β-lactoglobulin has emerged as an important model protein for the development of such materials. We here report that peptide hydrolysis is the rate-determining step for fibrillation of β-lactoglobulin in whey protein isolate. We also explore the observation that β-lactoglobulin nanofibrils of distinct morphologies are obtained by simply changing the initial protein concentration. We find that the morphological switch is related to different nucleation mechanisms and that the two classes of nanofibrils are associated with variations of the peptide building blocks. Based on the results, we propose that the balance between protein concentration and the hydrolysis rate determines the structure of the formed nanofibrils.
蛋白质自组装成淀粉样纳米纤维不仅是多种疾病中的关键事件，而且此类纤维还与有趣的生物学功能相关，并构成了新型生物基材料的有前景的组件。牛乳清蛋白β-乳球蛋白已成为开发此类材料的重要模型蛋白。我们在此报告，肽水解是乳清蛋白分离物中β-乳球蛋白纤维化的速率决定步骤。我们还探究了通过简单改变初始蛋白质浓度可获得不同形态的β-乳球蛋白纳米纤维这一观察结果。我们发现形态转变与不同的成核机制有关，并且两类纳米纤维与肽构建块的变化相关。基于这些结果，我们提出蛋白质浓度与水解速率之间的平衡决定了所形成纳米纤维的结构。
