Camus Marie-Stéphanie, Dos Santos Sonia, Chandravarkar Arunan, Mandal Bhubaneswar, Schmid Adrian W, Tuchscherer Gabriele, Mutter Manfred, Lashuel Hilal A
Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
Chembiochem. 2008 Sep 1;9(13):2104-12. doi: 10.1002/cbic.200800245.
Several amyloid-forming proteins are characterized by the presence of hydrophobic and highly amyloidogenic core sequences that play critical roles in the initiation and progression of amyloid fibril formation. Therefore targeting these sequences represents a viable strategy for identifying candidate molecules that could interfere with amyloid formation and toxicity of the parent proteins. However, the highly amyloidogenic and insoluble nature of these sequences has hampered efforts to develop high-throughput fibrillization assays. Here we describe the design and characterization of host-guest switch peptides that can be used for in vitro mechanistic and screening studies that are aimed at discovering aggregation inhibitors that target highly amyloidogenic sequences. These model systems are based on a host-guest system where the amyloidogenic sequence (guest peptide) is flanked by two beta-sheet-promoting (Leu-Ser)(n) oligomers as host sequences. Two host-guest peptides were prepared by using the hydrophobic core of Abeta comprising residues 14-24 (HQKLVFFAEDV) as the guest peptide with switch elements inserted within (peptide 1) or at the N and C termini of the guest peptide (peptide 2). Both model peptides can be triggered to undergo rapid self-assembly and amyloid formation in a highly controllable manner and their fibrillization kinetics is tuneable by manipulating solution conditions (for example, peptide concentration and pH). The fibrillization of both peptides reproduces many features of the full-length Abeta peptides and can be inhibited by known inhibitors of Abeta fibril formation. Our results suggest that this approach can be extended to other amyloid proteins and should facilitate the discovery of small-molecule aggregation inhibitors and the development of more efficacious anti-amyloid agents to treat and/or reverse the pathogenesis of neurodegenerative and systemic amyloid diseases.
几种形成淀粉样蛋白的蛋白质的特征在于存在疏水性且高度具有淀粉样蛋白生成能力的核心序列，这些序列在淀粉样纤维形成的起始和进展中起关键作用。因此，靶向这些序列是识别可能干扰亲本蛋白质淀粉样蛋白形成和毒性的候选分子的可行策略。然而，这些序列高度的淀粉样蛋白生成能力和不溶性阻碍了高通量纤维化测定方法的开发。在此，我们描述了主客体转换肽的设计与特性，这些肽可用于体外机制和筛选研究，旨在发现靶向高度淀粉样蛋白生成序列的聚集抑制剂。这些模型系统基于一个主客体系统，其中淀粉样蛋白生成序列（客体肽）两侧是两个促进β-折叠的（Leu-Ser）(n)寡聚物作为主体序列。通过使用包含14-24位残基（HQKLVFFAEDV）的Aβ疏水核心作为客体肽，并在客体肽内部（肽1）或N和C末端插入转换元件（肽2），制备了两种主客体肽。两种模型肽均可被触发以高度可控的方式快速进行自组装和淀粉样蛋白形成，并且通过控制溶液条件（例如肽浓度和pH值）可调节它们的纤维化动力学。两种肽的纤维化重现了全长Aβ肽的许多特征，并且可被已知的Aβ纤维形成抑制剂抑制。我们的结果表明，这种方法可扩展到其他淀粉样蛋白，应有助于发现小分子聚集抑制剂，并开发更有效的抗淀粉样蛋白药物来治疗和/或逆转神经退行性和全身性淀粉样疾病的发病机制。
