Retro-inversal of Intracellular Selected 尾-Amyloid-Interacting Peptides: Implications for a Novel Alzheimer鈥檚 Disease Treatment

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• 作者：Nicola Acerra ; Neil M. Kad ; Douglas A. Griffith ; Stanislav Ott ; Damian C. Crowther ; Jody M. Mason
• 刊名：Biochemistry
• 出版年：2014
• 出版时间：April 8, 2014
• 年：2014
• 卷：53
• 期：13
• 页码：2101-2111
• 全文大小：626K
• 年卷期：v.53,no.13(April 8, 2014)
• ISSN：1520-4995

文摘

The aggregation of 尾-amyloid (A尾) into toxic oligomers is a hallmark of Alzheimer鈥檚 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尾_1鈥?2. 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鈥搕rans-activating transcriptional activator peptide fusions. We demonstrate that the RI鈥損rotein fragment complementation assay approach can be used as a generalized method for deriving A尾-interacting peptides. This approach has subsequently led to several peptide candidates being further explored as potential treatments for Alzheimer鈥檚 disease.