Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300354, China.
Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300354, China.
J Inorg Biochem. 2018 Apr;181:56-64. doi: 10.1016/j.jinorgbio.2018.01.012. Epub 2018 Feb 2.
Dysfunctional accumulation of amyloid-β (Aβ) protein stimulated by Cu is considered as a key process in the pathogenesis of Alzheimer's disease (AD). Thus, bifunctional substances capable of chelating Cu and inhibiting Aβ aggregation are promising therapeutic agents against AD. Herein, a novel bifunctional decapeptide RTHLVFFARK-NH (RK10) was developed by integrating a metal chelating tripeptide (RTH) and an Aβ aggregation inhibitor Ac-LVFFARK-NH (LK7). The high selectivity of RK10 for Cu over other biologically relevant metal ions was demonstrated by isothermal titration calorimetry. RK10 bound Cu with a dissociation constant of 0.02 μM. This enabled RK10 to sequester Cu from Aβ-Cu species and to arrest the production of reactive oxygen species (ROS) catalyzed by Cu or Aβ-Cu species. Extensive physical, biophysical and biological studies indicate that RK10 targeted free and Cu-bound Aβ species, suppressed Aβ aggregation, and diminished the cytotoxicity induced by Aβ and Cu-mediated Aβ in cultured SH-SY5Y cells. Taken together, the results proved the excellent selective roles of RK10 in inhibiting Cu-mediated Aβ aggregation and eliminating ROS generation catalyzed by Cu/Aβ-Cu species. Thus, this work provided new insight into the design and development of potent bifunctional inhibitors against Aβ aggregation and cytotoxicity.
由 Cu 刺激的淀粉样蛋白-β (Aβ) 蛋白的功能失调积累被认为是阿尔茨海默病 (AD) 发病机制中的关键过程。因此，能够螯合 Cu 和抑制 Aβ聚集的双功能物质是治疗 AD 的有前途的治疗剂。在此，通过整合金属螯合三肽 (RTH) 和 Aβ 聚集抑制剂 Ac-LVFFARK-NH (LK7)，开发了一种新型双功能十肽 RTHLVFFARK-NH (RK10)。等温滴定量热法证明了 RK10 对 Cu 相对于其他生物相关金属离子的高选择性。RK10 与 Cu 的解离常数为 0.02 μM。这使 RK10 能够从 Aβ-Cu 物种中夺取 Cu，并阻止 Cu 或 Aβ-Cu 物种催化的活性氧 (ROS) 的产生。广泛的物理、生物物理和生物学研究表明，RK10 靶向游离和 Cu 结合的 Aβ 物种，抑制 Aβ 聚集，并减轻 Aβ 和 Cu 介导的 Aβ 在培养的 SH-SY5Y 细胞中诱导的细胞毒性。总之，这些结果证明了 RK10 在抑制 Cu 介导的 Aβ 聚集和消除 Cu/Aβ-Cu 物种催化的 ROS 生成方面的优异选择性作用。因此，这项工作为设计和开发针对 Aβ 聚集和细胞毒性的有效双功能抑制剂提供了新的见解。
