Nanoparticle-Mediated Assembly of Peptoid Nanosheets Functionalized with Solid-Binding Proteins: Designing Heterostructures for Hierarchy

Abstract

The fabrication of ordered architectures that intimately integrate polymer, protein and inorganic components remains difficult. Two promising building blocks to tackle this challenge are peptoids, peptide mimics capable of self-assembly into well-defined structures, and solid-binding peptides, which offer a biological path to controlled inorganic assembly. Here, we report on the synthesis of 3.3 nm-thick, thiol-reactive peptoid nanosheets from equimolar mixtures of unmodified and maleimide-derivatized versions of the Nbpe 6 Nce 6 oligomer, optimize the location of engineered cysteine residues in silica-binding derivatives of superfolder green fluorescent protein for maleimide conjugation, and react the two components to form proteinpeptoid hybrids exhibiting partial or uniform protein coverage on both of their sides. Using 10 nm silica nanoparticles, we trigger the stacking of these 2D structures into a multi-layer material comprised of alternating peptoid, protein and organic layers. This simple and modular approach to hierarchical hybrid synthesis should prove useful in bioimaging and photocatalysis applications.