Department of Biomedical Engineering, Healthcare Engineering Innovation Center, Khalifa University of Science and Technology, PO Box 127788, Abu Dhabi, United Arab Emirates.
Department of Chemistry, College of Arts and Science, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
Int J Biol Macromol. 2020 Apr 15;149:921-930. doi: 10.1016/j.ijbiomac.2020.01.267. Epub 2020 Jan 28.
The misfolding of proteins can lead to fibrillar and non-fibrillar deposits that are the hallmark of numerous human diseases. Inhibition of protein aggregation is considered as a promising strategy for the prevention of such diseases. Here we induced the fibrillar and non-fibrillar aggregates of hen egg white lysozyme (HEWL) at acidic (pH 3) and physiological (pH 7.4) environments. HEWL formed non-fibrillar aggregates rapidly at pH 7.4, whereas fibrillar HEWL aggregates were formed slowly at pH 3. Both fibrillar and non-fibrillar aggregates had cytotoxic effects on PC12 cells. Next, four organic acids, succinic acid, maleic acid, tartaric acid and citric acid, were tested for their inhibition potencies against fibrillar and non-fibrillar HEWL species. The four inhibitors were found to prevent the aggregation of HEWL at pH 7.4 with a reduction rate of over 95% as compared with the reduction rate of 42-58% for HEWL aggregation at pH 3. Other biophysical and computational analyses reveal that the candidate inhibitors have higher inhibition efficacy against HEWL monomers incubated at pH 7.4 than at pH 3. These results emphasize the importance of validating the newly identified aggregation drugs against different aggregate species, which would enhance the understanding of small molecules-induced protein aggregation inhibition.
蛋白质错误折叠会导致纤维状和非纤维状沉积物，这是许多人类疾病的标志。抑制蛋白质聚集被认为是预防此类疾病的一种有前途的策略。在这里，我们在酸性（pH 3）和生理（pH 7.4）环境下诱导了鸡卵清白溶菌酶（HEWL）的纤维状和非纤维状聚集体。HEWL 在 pH 7.4 下迅速形成非纤维状聚集体，而纤维状 HEWL 聚集体则在 pH 3 下缓慢形成。纤维状和非纤维状聚集体都对 PC12 细胞具有细胞毒性作用。接下来，我们测试了四种有机酸（琥珀酸、马来酸、酒石酸和柠檬酸）对纤维状和非纤维状 HEWL 物种的抑制效力。这四种抑制剂都能在 pH 7.4 下抑制 HEWL 的聚集，与在 pH 3 下 HEWL 聚集的减少率 42-58%相比，减少率超过 95%。其他生物物理和计算分析表明，与在 pH 3 下孵育的 HEWL 单体相比，候选抑制剂对在 pH 7.4 下孵育的 HEWL 单体具有更高的抑制效果。这些结果强调了对不同聚集体物种验证新鉴定的聚集药物的重要性，这将有助于加深对小分子诱导的蛋白质聚集抑制的理解。
