Department of Medicinal Chemistry, Center for Frontier Research in Medicinal Science, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto, Japan.
Bioorg Med Chem. 2011 Mar 1;19(5):1729-33. doi: 10.1016/j.bmc.2011.01.021. Epub 2011 Jan 25.
The O-acyl isopeptide of Aβ1-42 (1), possessing an ester bond at the Gly(25)-Ser(26) sequence, is a water-soluble and non-aggregative precursor molecule and is capable of production of monomer Aβ1-42. The SDS-PAGE result showed that the Aβ1-42, produced from 1, adopted monomeric state at first and then self-assembled to oligomer. The oligomeric state was stabilized by nordihydroguaiaretic acid. The Thioflavin-T (ThT) fluorescence intensity derived from Aβ1-42 (generated from 1) was suppressed by various aggregation inhibitors. Finally, 1 could generate Aβ1-42 via the O-to-N acyl migration under cellular medium conditions and the produced Aβ1-42 exhibited cytotoxicity against PC12 cells. These results suggest that the click peptide system, which enables us to predominantly produce monomer Aβ1-42 under physiological conditions, would be adoptable to various biochemical and biophysical experiments including cellular system to investigate the functions of Aβ1-42.
Aβ1-42 的 O-酰基异肽（1）在甘氨酸（25）-丝氨酸（26）序列处具有酯键，是一种水溶性的、非聚集的前体分子，能够产生单体 Aβ1-42。SDS-PAGE 结果表明，由 1 产生的 Aβ1-42 首先采用单体状态，然后自组装成寡聚物。这种寡聚状态被 nordihydroguaiaretic acid（NDGA）稳定。来自 Aβ1-42（由 1 产生）的 Thioflavin-T（ThT）荧光强度被各种聚集抑制剂抑制。最后，1 在细胞介质条件下通过 O 到 N 酰基迁移生成 Aβ1-42，产生的 Aβ1-42 对 PC12 细胞表现出细胞毒性。这些结果表明，点击肽系统可以使我们在生理条件下主要产生单体 Aβ1-42，可适用于包括细胞系统在内的各种生化和生物物理实验，以研究 Aβ1-42 的功能。
