Binding of methylene blue to a surface cleft inhibits the oligomerization and fibrillization of prion protein
Binding of methylene blue to a surface cleft inhibits the oligomerization and fibrillization of prion protein
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DOI：
10.1016/j.bbadis.2012.09.005
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发表时间：
2013-01-01
影响因子：
6.2
通讯作者：
Zagari, Adriana
中科院分区：
文献类型：
--
作者：
Cavaliere, Paola;Torrent, Joan;Zagari, Adriana
包括朊病毒病在内的神经退行性蛋白质错误折叠疾病的共同特征是积累特定的错误折叠蛋白，其分子机制密切相关。错误折叠的朊病毒蛋白（PrP）产生可溶性寡聚体，这些寡聚体反过来聚集成淀粉样纤维。预防这些实体的形成，与所产生的异常PrP的神经毒性和/或感染性特性至关重要，代表了改善朊病毒病的有吸引力的治疗策略。我们将注意力集中在亚甲蓝（MB）上，这是一种具有良好特征的药物，正在研究用于治疗阿尔茨海默病和其他神经退行性疾病。在这里，我们进行了一项体外研究MB对人，羊和小鼠PrP的寡聚化和fietrization的影响。我们证明，MB影响PrP低聚的动力学，并减少约30%的低聚物的量，在pH依赖性的方式，通过使用SLS和DSC方法。此外，TEM图像显示，MB完全抑制纤维形成在PrP：MB摩尔比为1：2。最后，NMR揭示了PrP和MB之间的直接相互作用，这是映射在一个表面裂缝，包括蛋白质的纤维形成区域。我们的研究结果允许survival的作用机制，其中MB结合到PrP表面显着干扰的途径，对寡聚体和纤维。因此，MB可以被认为是一种通用的抗聚集化合物，对蛋白质病起作用。(C)2012爱思唯尔有限公司版权所有。
Neurodegenerative protein misfolding diseases, including prionopathies, share the common feature of accumulating specific misfolded proteins, with a molecular mechanism closely related. Misfolded prion protein (PrP) generates soluble oligomers that, in turn, aggregate into amyloid fibers. Preventing the formation of these entities, crucially associated with the neurotoxic and/or infectious properties of the resulting abnormal PrP, represents an attractive therapeutic strategy to ameliorate prionopathies. We focused our attention into methylene blue (MB), a well-characterized drug, which is under study against Alzheimer's disease and other neurodegenerative disorders. Here, we have undertaken an in vitro study on the effects of MB on oligomerization and fibrillization of human, ovine and murine PrP. We demonstrated that MB affects the kinetics of PrP oligomerization and reduces the amount of oligomer of about 30%, in a pH-dependent manner, by using SLS and DSC methodologies. Moreover, TEM images showed that MB completely suppresses fiber formation at a PrP:MB molar ratio of 1:2. Finally, NMR revealed a direct interaction between PrP and MB, which was mapped on a surface cleft including a fibrillogenic region of the protein. Our results allowed to surmise a mechanism of action in which the MB binding to PrP surface markedly interferes with the pathway towards oligomers and fibres. Therefore MB could be considered as a general anti-aggregation compound, acting against proteinopathies. (C) 2012 Elsevier B.V. All rights reserved.