Many one-dimensional (1D) nanostructures are constructed by self-assembly of peptides or peptide conjugates containing a short β-sheet sequence as the core building motif essential for the intermolecular hydrogen bonding that promotes directional, anisotropic growth of the resultant assemblies. While this molecular engineering strategy has led to the successful production of a plethora of bioactive filamentous β-sheet assemblies for interfacing with biomolecules and cells, concerns associated with effective presentation of α-helical epitopes and their function preservation have yet to be resolved. In this context, we report on the direct conjugation of the protein A mimicking peptide Z33, a motif containing two α-helices, to linear hydrocarbons to create self-assembling immuno-amphiphiles (IAs). Our results suggest that the resulting amphiphilic peptides can, despite lacking the essential β-sheet segment, effectively associate under physiological conditions into supramolecular immunofibers (IFs) while preserving their native α-helical conformation. Isothermal titration calorimetry (ITC) measurements confirmed that these self-assembling immunofibers can bind to the human immunoglobulin G class 1 (IgG1) with high specificity at pH 7.4, but with significantly weakened binding at pH 2.8. We further demonstrated the accessibility of Z33 ligand in the immunofibers using transmission electron microscopy (TEM) and confocal imaging. We believe these results shed important light into the supramolecular engineering of α-helical peptides into filamentous assemblies that may possess an important potential for antibody isolation.

许多一维（1D）纳米结构是通过自组装包含短β- sheet序列作为分子间氢键所必需的核心构建基序的肽或肽缀合物的自组装而形成的，分子间氢键促进了所得组装体的定向各向异性生长。尽管这种分子工程策略已经成功地生产了许多与生物分子和细胞连接的具有生物活性的丝状β-折叠组件，但是与α-螺旋表位的有效呈递及其功能保存有关的问题仍未解决。在这种情况下，我们报道了模仿肽Z33的蛋白A的直接缀合，Z33是包含两个α的基序-螺旋，生成线性自组装的免疫两亲物（IAs）。我们的结果表明，尽管缺少必需的β-折叠片段，但所得到的两亲性肽仍可以在生理条件下有效缔合为超分子免疫纤维（IFs），同时保留其天然的α-螺旋构象。等温滴定热法（ITC）测量证实，这些自组装免疫纤维可以在pH 7.4时以高特异性与人免疫球蛋白G 1类（IgG1）结合，但在pH 2.8时结合力显着减弱。我们进一步证明了Z33配体在免疫纤维中的可及性透射电子显微镜（TEM）和共聚焦成像。我们相信这些结果为α-螺旋肽的超分子工程化为丝状组装提供了重要的启示，这些组装可能具有重要的抗体分离潜力。