Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy.
Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
J Struct Biol. 2019 Nov 1;208(2):165-173. doi: 10.1016/j.jsb.2019.08.011. Epub 2019 Aug 29.
The inherent amyloidogenic potentialof wild type transthyretin (TTR) is enhanced by a large number of point mutations, which destabilize the TTR tetramer, thereby promoting its disassembly and pathological aggregation responsible for TTR-related amyloidosis. TTR stabilizers are able to interact with the thyroxine-binding sites of TTR, stabilizing its tetrameric native state and inhibiting amyloidogenesis. Herein, we report on in vitro, ex vivo, and X-ray analyses to assess the TTR structural stabilization by analogues of flurbiprofen, a non-steroidal anti-inflammatory drug (NSAID). Overall, considering together binding selectivity and protective effects on TTR native structure by flurbiprofen analogues in the presence of plasma proteins, as determined by Western Blot,the aforementioned properties of analyzed compounds appear to be better (CHF5075 and CHF4802) or similar (CHF4795) or worse (CHF5074, also known as CSP-1103) as compared to those of diflunisal, used as a reference TTR stabilizer. Molecular details of the determinants affecting the interactionsof CHF5075, CHF4802, and CHF4795 with wild type TTRand of CHF5074 withtheamyloidogenic A25TTTR variant havebeen elucidated by X-ray analysis. Distinct interactions with TTR appear to characterize flurbiprofen analogues and the NSAID diflunisal and its analogues as TTR stabilizers. Relationships between stabilizing effect on TTR by flurbiprofen analogues determined experimentally and molecular details of their interactions with TTR have been established, providing the rationale for their protective effects on the native protein structure.
野生型转甲状腺素蛋白（TTR）的固有淀粉样变性潜能受到大量点突变的增强，这些点突变会破坏 TTR 四聚体，从而促进其解组装和病理性聚集，导致 TTR 相关性淀粉样变性。TTR 稳定剂能够与 TTR 的甲状腺素结合位点相互作用，稳定其四聚体天然状态并抑制淀粉样变性形成。在此，我们报告了体外、离体和 X 射线分析结果，以评估非甾体抗炎药（NSAID）氟比洛芬类似物对 TTR 结构的稳定作用。总的来说，综合考虑氟比洛芬类似物与血浆蛋白共存时对 TTR 天然结构的结合选择性和保护作用（通过 Western Blot 测定），与作为参考 TTR 稳定剂的双氯芬酸相比，所分析化合物的上述特性似乎更好（CHF5075 和 CHF4802）或相似（CHF4795）或更差（CHF5074，也称为 CSP-1103）。通过 X 射线分析阐明了影响 CHF5075、CHF4802 和 CHF4795 与野生型 TTR 相互作用以及 CHF5074 与淀粉样变性 A25T TTR 变体相互作用的分子细节。氟比洛芬类似物和 NSAID 双氯芬酸及其类似物似乎与 TTR 具有独特的相互作用，可将其作为 TTR 稳定剂。已经建立了氟比洛芬类似物对 TTR 的稳定作用与它们与 TTR 相互作用的分子细节之间的关系，为它们对天然蛋白质结构的保护作用提供了依据。
