Engineering the Peptide Coassembly into 2D Architectures for Enhanced DNA Interactions

The design and synthesis of biomimetic molecules, guided by the principles of molecular architectonics, represent significant advancements in the development of functional materials. This approach facilitates the systematic investigation of how amino acid sequences influence the structural and functional properties of oligopeptides. In this study, we present the design and synthesis of decapeptides with opposite polarity, consisting of specific periodic amino acid sequences such as W 5 K 5 (W: tryptophan, K: lysine) and W 5 E 5 (W: tryptophan, E: glutamic acid), which spontaneously assemble into peptide nanoparticles in aqueous media. A 1:1 mixture of these peptides undergoes coassembly in a phosphate buffer, transitioning from nanoparticles to hierarchical architecture, specifically two-dimensional (2D) sheets with lateral dimension of several micrometers. The assembly process is driven by electrostatic interactions between oppositely charged decapeptides and the uniform distribution of hydrophobic and hydrophilic moieties. The formation and stability of these 2D sheets were studied by using various microscopy and spectroscopy techniques. The 2D peptide assemblies, with their large surface area and structural flexibility, demonstrate significant potential for biological applications, such as DNA interaction. Understanding and optimizing DNA–peptide interactions are essential for advancing applications in gene delivery, biosensing, and nanobiotechnology. This study investigates how coassembled 2D peptide nanostructures can enhance DNA-binding interactions. The coassembled 2D sheets exhibited markedly higher DNA interaction efficiency compared to individual peptide nanoparticles. This study offers a straightforward yet innovative strategy for fabricating peptide-based 2D materials via molecular assembly, providing a promising platform for advancements in DNA nanotechnology and related fields.