Structural Evidence of Amyloid Fibril Formation in the Putative Aggregation Domain of TDP-43

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• 作者：Miguel Mompe谩n ; Rub茅n Herv谩s ; Yunyao Xu ; Timothy H. Tran ; Corrado Guarnaccia ; Emanuele Buratti ; Francisco Baralle ; Liang Tong ; Mariano Carri贸n-V谩zquez ; Ann E. McDermott ; Douglas V. Laurents
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2015
• 出版时间：July 2, 2015
• 年：2015
• 卷：6
• 期：13
• 页码：2608-2615
• 全文大小：408K
• ISSN：1948-7185

文摘

TDP-43 can form pathological proteinaceous aggregates linked to ALS and FTLD. Within the putative aggregation domain, engineered repeats of residues 341鈥?66 can recruit endogenous TDP-43 into aggregates inside cells; however, the nature of these aggregates is a debatable issue. Recently, we showed that a coil to 尾-hairpin transition in a short peptide corresponding to TDP-43 residues 341鈥?57 enables oligomerization. Here we provide definitive structural evidence for amyloid formation upon extensive characterization of TDP-43(341鈥?57) via chromophore and antibody binding, electron microscopy (EM), solid-state NMR, and X-ray diffraction. On the basis of these findings, structural models for TDP-43(341鈥?57) oligomers were constructed, refined, verified, and analyzed using docking, molecular dynamics, and semiempirical quantum mechanics methods. Interestingly, TDP-43(341鈥?57) 尾-hairpins assemble into a novel parallel 尾-turn configuration showing cross-尾 spine, cooperative H-bonding, and tight side-chain packing. These results expand the amyloid foldome and could guide the development of future therapeutics to prevent this structural conversion.