Structure Optimization of the Toxic Conformation Model of Amyloid β42 by Intramolecular Disulfide Bond Formation
Structure Optimization of the Toxic Conformation Model of Amyloid β42 by Intramolecular Disulfide Bond Formation
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β42淀粉样蛋白毒性构象模型分子内二硫键形成的结构优化
DOI：
10.1002/cbic.202200029
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发表时间：
2022
期刊：
影响因子：
3.2
通讯作者：
Irie Kazuhiro
中科院分区：
文献类型：
--
作者：
Matsushima Yuka;Irie Yumi;Kageyama Yusuke;Bellier Jean‐Pierre;Tooyama Ikuo;Maki Takahito;Kume Toshiaki;Yanagita Ryo C.;Irie Kazuhiro
β 淀粉样蛋白 (Aβ) 寡聚物在阿尔茨海默病的病理学中发挥着关键作用。最近，我们报道了构象限制的 Aβ42，其通过 17/28 位半胱氨酸残基形成分子内二硫键，形成具有有效细胞毒性的稳定寡聚物。为了进一步优化该化合物作为有毒构象异构体模型，我们在 17/28 位合成了半胱氨酸和高半胱氨酸组合的三种类似物。 Cys-Cys、Cys-homoCys 或homoCys-Cys 类似物（但非homoCys-homoCys 类似物）即使在 10 nM 的浓度下也对 SH-SY5Y 和 THP-1 细胞表现出有效的细胞毒性。相反，16/29或18/27位构象限制类似物的细胞毒性明显弱于野生型Aβ42。此外，硫黄素-T测定、非变性凝胶电泳和形态学研究表明，这些构象限制类似物中的大多数以寡聚状态存在于细胞培养基中，这表明Aβ42的毒性构象而不是寡聚状态对于诱导细胞毒性至关重要。
Amyloid β (Aβ) oligomers play a critical role in the pathology of Alzheimer's disease. Recently, we reported that a conformation‐restricted Aβ42 with an intramolecular disulfide bond through cysteine residues at positions 17/28 formed stable oligomers with potent cytotoxicity. To further optimize this compound as a toxic conformer model, we synthesized three analogues with a combination of cysteine and homocysteine at positions 17/28. The analogues with Cys‐Cys, Cys‐homoCys, or homoCys‐Cys, but not the homoCys‐homoCys analogue, exhibited potent cytotoxicity against SH‐SY5Y and THP‐1 cells even at 10 nM. In contrast, the cytotoxicity of conformation‐restricted analogues at positions 16/29 or 18/27 was significantly weaker than that of wild‐type Aβ42. Furthermore, thioflavin‐T assay, non‐denaturing gel electrophoresis, and morphological studies suggested that the majority of these conformation‐restricted analogues exists in an oligomeric state in cell culture medium, indicating that the toxic conformation of Aβ42, rather than the oligomeric state, is essential to induce cytotoxicity.