Peptoids are biofunctional N-substituted glycine peptidomimics. Their self-assembly is of fundamental interest because they demonstrate alternatives to conventional peptide structures based on backbone chirality and beta-sheet hydrogen bonding. The search for self-assembling, water-soluble "minimal" sequences, be they peptide or peptidomimic, is a further challenge. Such sequences are highly desired for their compatibility with biomacromolecules and convenient synthesis for broader application. We report the self-assembly of a set of trimeric, water-soluble α-peptoids that exhibit a relatively low critical aggregation concentration (CAC ∼ 0.3 wt %). Cryo-EM and angle-resolved DLS show different sequence-dependent morphologies, namely uniform ca. 6 nm wide nanofibers, sheets, and clusters of globular assemblies. Absorbance and fluorescence spectroscopies indicate unique phenyl environments for π-interactions in the highly ordered nanofibers. Assembly of our peptoids takes place when the sequences are fully ionized, representing a departure from superficially similar amyloid-type hydrogen-bonded peptide nanostructures and expanding the horizons of assembly for sequence-specific bio- and biomimetic macromolecules.

中文翻译：

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最小拟肽序列的自组装。

类肽是生物功能的N-取代的甘氨酸肽组。它们的自组装具有根本的意义，因为它们证明了基于骨架手性和β-折叠氢键的常规肽结构的替代品。寻找自组装的水溶性“最小”序列，无论它们是肽还是肽组的，是进一步的挑战。由于它们与生物大分子的相容性和方便的合成以用于更广泛的应用，因此非常需要这样的序列。我们报道了一组三聚体水溶性α-类肽的自组装，这些肽类蛋白显示出相对较低的临界聚集浓度（CAC〜0.3 wt％）。低温电磁和角度分辨DLS显示不同的序列依赖性形态，即均匀的ca。6纳米宽的纳米纤维，薄片和球状组件簇。吸光度和荧光光谱表明，在高度有序的纳米纤维中，π相互作用的独特苯基环境。当序列被完全电离时，我们的类肽就会组装，这与表面类似的淀粉样蛋白型氢键肽纳米结构背道而驰，并扩大了序列特异性生物和仿生大分子的组装视野。