Monoclonal Antibodies Recognize Distinct Conformational Epitopes Formed by Polyglutamine in a Mutant Huntingtin Fragment
Monoclonal Antibodies Recognize Distinct Conformational Epitopes Formed by Polyglutamine in a Mutant Huntingtin Fragment
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DOI：
10.1074/jbc.m109.016923
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发表时间：
2009-08-07
影响因子：
4.8
通讯作者：
Muchowski, Paul J.
中科院分区：
文献类型：
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作者：
Legleiter, Justin;Lotz, Gregor P.;Muchowski, Paul J.
亨廷顿病（HD）是由亨廷顿蛋白（htt）的N-末端区域中的多聚谷氨酰胺（polyQ）结构域的扩增引起的神经退行性疾病。PolyQ扩增超过35-40导致与htt聚集成包涵体相关的疾病。已经假设扩展的polyQ结构域采用属于不同聚集途径的多种潜在毒性构象。在这里，我们使用原子力显微镜分析一组抗htt抗体（MW 1-MW 5，MW 7，MW 8和3B 5 H10）对聚集体形成和突变htt-exon 1片段稳定性的影响。两种抗体，MW 7（聚脯氨酸特异性）和3B 5 H10（polyQ特异性），完全抑制原纤维形成和解聚预形成的原纤维，而其他polyQ特异性抗体对聚集有广泛不同的影响。这些结果表明，扩展的polyQ结构域在溶液中采用多种构象，这些构象可以通过单克隆抗体容易地区分，这对于理解polyQ毒性的结构基础和开发基于胞内抗体的HD治疗方法具有重要意义。
Huntington disease (HD) is a neurodegenerative disorder caused by an expansion of a polyglutamine (polyQ) domain in the N-terminal region of huntingtin (htt). PolyQ expansion above 35-40 results in disease associated with htt aggregation into inclusion bodies. It has been hypothesized that expanded polyQ domains adopt multiple potentially toxic conformations that belong to different aggregation pathways. Here, we used atomic force microscopy to analyze the effect of a panel of anti-htt antibodies (MW1-MW5, MW7, MW8, and 3B5H10) on aggregate formation and the stability of a mutant htt-exon1 fragment. Two antibodies, MW7 (polyproline-specific) and 3B5H10 (polyQ-specific), completely inhibited fibril formation and disaggregated preformed fibrils, whereas other polyQ-specific antibodies had widely varying effects on aggregation. These results suggest that expanded polyQ domains adopt multiple conformations in solution that can be readily distinguished by monoclonal antibodies, which has important implications for understanding the structural basis for polyQ toxicity and the development of intrabody-based therapeutics for HD.