Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina.
Proc Natl Acad Sci U S A. 2009 Dec 15;106(50):21057-62. doi: 10.1073/pnas.0902603106. Epub 2009 Nov 30.
The identification of aggregation inhibitors and the investigation of their mechanism of action are fundamental in the quest to mitigate the pathological consequences of amyloid formation. Here, characterization of the structural and mechanistic basis for the antiamyloidogenic effect of phthalocyanine tetrasulfonate (PcTS) on alpha-synuclein (AS) allowed us to demonstrate that specific aromatic interactions are central for ligand-mediated inhibition of amyloid formation. We provide evidence indicating that the mechanism behind the antiamyloidogenic effect of PcTS is correlated with the trapping of prefibrillar AS species during the early stages of the assembly process. By using NMR spectroscopy, we have located the primary binding region for PcTS to a specific site in the N terminus of AS, involving the amino acid Tyr-39 as the anchoring residue. Moreover, the residue-specific structural characterization of the AS-PcTS complex provided the basis for the rational design of nonamyloidogenic species of AS, highlighting the role of aromatic interactions in driving AS amyloid assembly. A comparative analysis with other proteins involved in neurodegenerative disorders reveals that aromatic recognition interfaces might constitute a key structural element to target their aggregation pathways. These findings emphasize the use of aggregation inhibitors as molecular probes to assess structural and toxic mechanisms related to amyloid formation and the potential of small molecules as therapeutics for amyloid-related pathologies.
鉴定聚集抑制剂并研究其作用机制是减轻淀粉样蛋白形成所致病理后果的基础。在这里，我们对酞菁四磺酸钠（PcTS）对α-突触核蛋白（AS）的抗淀粉样蛋白形成作用的结构和机制基础进行了表征，证明了特定的芳香相互作用对于配体介导的抑制淀粉样蛋白形成是至关重要的。我们提供的证据表明，PcTS 抗淀粉样蛋白形成作用的机制与在组装过程的早期阶段捕获前纤维状 AS 物种有关。通过使用 NMR 光谱，我们确定了 PcTS 与 AS 的 N 端特定位点的主要结合区域，涉及作为锚定残基的氨基酸 Tyr-39。此外，AS-PcTS 复合物的残基特异性结构表征为 AS 的非淀粉样蛋白形成物种的合理设计提供了基础，突出了芳香相互作用在驱动 AS 淀粉样蛋白组装中的作用。与其他参与神经退行性疾病的蛋白质进行的比较分析表明，芳香识别界面可能构成靶向其聚集途径的关键结构元件。这些发现强调了将聚集抑制剂用作评估与淀粉样蛋白形成相关的结构和毒性机制的分子探针的重要性，并表明小分子作为淀粉样蛋白相关病理学的治疗药物具有潜力。
