Co-assembly of Peptide Amphiphiles and Lipids into Supramolecular Nanostructures Driven by Anion−π Interactions

Abstract

Co-assembly of binary systems driven by specific non-covalent interactions can greatly expand the structural and functional space of supramolecular nanostructures. We report here on the self-assembly of peptide amphiphiles and fatty acids driven primarily by anion-π interactions. The peptide sequences investigated were functionalized with a perfluorinated phenylalanine residue to promote anion-π interactions with carboxylate headgroups in fatty acids. These interactions were verified here by NMR and circular dichroism experiments as well as investigated using atomistic simulations. Positioning the aromatic units close to the N-terminus of the peptide backbone near the hydrophobic core of cylindrical nanofibers leads to strong anion-π interactions between both components. With a low content of dodecanoic acid in this position, the cylindrical morphology is preserved. However, as the aromatic units are moved along the peptide backbone away from the hydrophobic core, the interactions with dodecanoic acid transform the cylindrical supramolecular morphology into ribbon-like structures. Increasing the ratio of dodecanoic acid to PA leads to either the formation of large vesicles in the binary systems where the anion-π interactions are strong, or a heterogeneous mixture of assemblies when the peptide amphiphiles associate weakly with dodecanoic acid. Our findings reveal how co-assembly involving designed specific interactions can drastically change supramolecular morphology and even cross from nano to micro scales.

Solvent‐Controlled Assembly of Aromatic Glutamic Dendrimers for Efficient Luminescent Color Conversion

“…For instance, Zhang and Wang developed a series of noncovalently bonded complexes namely supramolecular amphiphiles capable of self‐organizing into versatile nanoarchitectures . Stupp and co‐workers designed supramolecular nanostructures from the coassembly of peptide amphiphiles and lipids based on their anion–π interactions . Kinetically, factors such as temperature, concentration, pH, and solvent should be considered during the self‐assembly, as these parameters might affect the site and rate of nucleation and growth, as well as corresponding aggregation behavior.…”

Selective Coassembly of Aromatic Amino Acids to Fabricate Hydrogels with Light Irradiation‐Induced Emission for Fluorescent Imprint

“…For example, Stupp and co‐workers designed peptide amphiphile analogs with same alkyl chains and amino acid sequences but different terminal groups to enhance the hydrogen bonding between components, showing excellent coassembly phenomenon . Recently, they further implanted one fluorinated phenylalanine in peptide sequences to strengthen the anion–π interaction, allowing for successful preparation of peptide/dodecanoic acid binary coassemblies . We found that the coassembly behavior between pyrene and naphthalene dicarboximide appended glutamate building blocks was concentration‐dependent (a kinetic control), and higher concentration would facilitate the coassembly and improve the intercomponent energy transfer .…”

Self‐assembled chiral nanostructures of amphiphilic peptide: from single molecule to aggregate

“…In other aspect, self-assembled amphiphilic peptide nanostructures have been considered not only as pathological aggregates but also as advanced materials in material sciences [6][7][8]13,14,[23][24][25][26][27]34,[37][38][39][40][41][42][43], such as for biocatalyst [37][38][39][40][41][42][43], stabilizing diverse membrane as a fundamental component [15][16][17][18]. The final function of peptides depends on the self-assembled and properties of hierarchical structures, the mechanisms of peptide aggregation (the driving forces needed to understand) [44][45][46]. Appropriate model systems are indispensable.…”