Retro-inversal of Intracellular Selected β-Amyloid-Interacting Peptides: Implications for a Novel Alzheimer's Disease Treatment
Retro-inversal of Intracellular Selected β-Amyloid-Interacting Peptides: Implications for a Novel Alzheimer's Disease Treatment
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DOI：
10.1021/bi5001257
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发表时间：
2014-04-08
期刊：
影响因子：
2.9
通讯作者：
Mason, Jody M.
中科院分区：
文献类型：
--
作者：
Acerra, Nicola;Kad, Neil M.;Mason, Jody M.
β-淀粉样蛋白（A β）聚集成毒性低聚物是阿尔茨海默病病理学的标志。在这里，我们提出了一种新的方法，用于开发肽能够防止淀粉样蛋白聚集的基础上，以前选择的天然全L肽结合A β（1-42）。使用细胞内选择系统，通过竞争选择进一步筛选成功的文库成员以鉴定能够降低淀粉样蛋白水平的最有效的肽。为了避免这些结构的稳定性和蛋白酶作用引起的潜在问题，我们用D残基取代了所有L残基并颠倒了序列。因此，这些反转（RI）肽类似物包含保持天然肽的总体拓扑顺序的反向序列。我们的研究结果表明，在阻断和逆转淀粉样蛋白形成的功效保持，同时引入所需的性质的肽。硫磺素-T测定、圆二色性和斜角荧光显微术共同表明RI肽可以降低淀粉样蛋白负荷，而3-（4，5-二甲基噻唑-2-基）-2，5-二苯基四唑溴化物测定证明细胞毒性适度降低。这些结论得到加强，使用果蝇的研究，以监测蛹孵化率和苍蝇运动活性的存在下，通过RI-反式激活转录激活肽融合提供的RI肽。我们证明，RI-蛋白质片段互补测定方法可以用作一种通用的方法，用于获得A β相互作用肽。这种方法随后导致几种肽候选物被进一步探索作为阿尔茨海默病的潜在治疗方法。
The aggregation of beta-amyloid (A beta) into toxic oligomers is a hallmark of Alzheimer's disease pathology. Here we present a novel approach for the development of peptides capable of preventing amyloid aggregation based upon the previous selection of natural all-L peptides that bind A beta(1-42). Using an intracellular selection system, successful library members were further screened via competition selection to identify the most effective peptides capable of reducing amyloid levels. To circumvent potential issues arising from stability and protease action for these structures, we have replaced all L residues with D residues and inverted the sequence. These retro-inverso (RI) peptide analogues therefore encompass reversed sequences that maintain the overall topological order of the native peptides. Our results demonstrate that efficacy in blocking and reversing amyloid formation is maintained while introducing desirable properties to the peptides. Thioflavin-T assays, circular dichroism, and oblique angle fluorescence microscopy collectively indicate that RI peptides can reduce amyloid load, while 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays demonstrate modest reductions in cell toxicity. These conclusions are reinforced using Drosophila melanogaster studies to monitor pupal hatching rates and fly locomotor activity in the presence of RI peptides delivered via RI-trans-activating transcriptional activator peptide fusions. We demonstrate that the RI-protein fragment complementation assay approach can be used as a generalized method for deriving A beta-interacting peptides. This approach has subsequently led to several peptide candidates being further explored as potential treatments for Alzheimer's disease.