The peptide sequence KLVFF resembles the hydrophobic core of the Aβ peptide known to form amyloid plaques in Alzheimer’s disease. Starting from its retro-inverso peptide, we have synthesized three generations of peptidomimetics. Step by step natural amino acids have been replaced by aromatic building blocks accessible from the Pd-catalyzed Catellani reaction. The final compound 18 is stable against proteolytic decay and largely prevents the aggregation of Aβ1–42 over extended periods of time. The activity of the new inhibitors was tested first by fluorescence correlation spectroscopy. For closer examination of compound 18, additional techniques were also applied: laser-induced liquid bead ion desorption mass spectrometry, confocal laser scanning microscopy, thioflavin T fluorescence, and gel electrophoresis. Compound 18 not only retards the aggregation of chemically synthesized Aβ but also can partially dissolve the oligomeric structures. Thioflavin binding mature fibrils, however, seem to resist the inhibitor.
肽序列 KLVFF 与已知在阿尔茨海默病中形成淀粉样斑块的 Aβ 肽的疏
水核心相似。从它的逆向肽开始,我们合成了三代拟肽物。天然
氨基酸逐步被
钯催化的卡泰拉尼(Catellani)反应可获得的芳香族结构单元所取代。最终的化合物 18 能稳定地抵抗蛋白分解,并在很大程度上长时间阻止 Aβ1-42 的聚集。新
抑制剂的活性首先通过荧光相关光谱进行了测试。为了更仔细地检测化合物 18,还采用了其他技术:激光诱导液珠离子解吸质谱法、激光共聚焦扫描显微镜、
硫黄素 T 荧光法和凝胶电泳法。化合物 18 不仅能延缓
化学合成 Aβ 的聚集,还能部分溶解其低聚结构。不过,与
硫黄结合的成熟纤维似乎对
抑制剂有抵抗力。