High-resolution structures of oligomers formed by the β-amyloid peptide, Aβ, are important for understanding the molecular basis of Alzheimer’s disease. Dimers of Aβ are linked to the pathogenesis and progression of Alzheimer’s disease, and tetramers of Aβ are neurotoxic. This paper reports the X-ray crystallographic structures of dimers and tetramers, as well as an octamer, formed by a peptide derived from the central and C-terminal regions of Aβ. In the crystal lattice, the peptide assembles to form two different dimers—an antiparallel β-sheet dimer and a parallel β-sheet dimer—that each further self-assemble to form two different tetramers—a sandwich-like tetramer and a twisted β-sheet tetramer. The structures of these dimers and tetramers derived from Aβ serve as potential models for dimers and tetramers of full-length Aβ that form in vitro and in Alzheimer’s disease-afflicted brains.

中文翻译：

---

X 射线晶体学揭示了从 Aβ16-36 衍生的 β-发夹的平行和反平行 β-片二聚体，它们组装形成不同的四聚体。

由 β-淀粉样肽 Aβ 形成的低聚物的高分辨率结构对于理解阿尔茨海默病的分子基础非常重要。Aβ 的二聚体与阿尔茨海默病的发病机制和进展有关，而 Aβ 的四聚体具有神经毒性。本文报告了二聚体和四聚体以及八聚体的 X 射线晶体结构，由来自中央和C的肽形成。-Aβ 的末端区域。在晶格中，肽组装形成两个不同的二聚体——一个反平行的 β-折叠二聚体和一个平行的 β-折叠二聚体——每个进一步自组装形成两个不同的四聚体——一个夹心四聚体和一个扭曲的 β-片状四聚体。这些源自 Aβ 的二聚体和四聚体的结构可作为在体外和受阿尔茨海默病影响的大脑中形成的全长 Aβ 的二聚体和四聚体的潜在模型。