Self-assembly of amphiphilic dendritic dipeptides into helical pores

Abstract

Natural pore-forming proteins act as viral helical coats and transmembrane channels, exhibit antibacterial activity and are used in synthetic systems, such as for reversible encapsulation or stochastic sensing. These diverse functions are intimately linked to protein structure. The close link between protein structure and protein function makes the design of synthetic mimics a formidable challenge, given that structure formation needs to be carefully controlled on all hierarchy levels, in solution and in the bulk. In fact, with few exceptions, synthetic pore structures capable of assembling into periodically ordered assemblies that are stable in solution and in the solid state have not yet been realized. In the case of dendrimers, covalent and non-covalent coating and assembly of a range of different structures has only yielded closed columns. Here we describe a library of amphiphilic dendritic dipeptides that self-assemble in solution and in bulk through a complex recognition process into helical pores. We find that the molecular recognition and self-assembly process is sufficiently robust to tolerate a range of modifications to the amphiphile structure, while preliminary proton transport measurements establish that the pores are functional. We expect that this class of self-assembling dendrimers will allow the design of a variety of biologically inspired systems with functional properties arising from their porous structure.

Self-assembling subnanometer pores with unusual mass-transport properties

“…Biological nanotubular complexes, such as the non-selective pore formed by α-hemolysin 2 , and the highly selective channels of ions 3 and water 4 , provide some of the most spectacular examples of supramolecular assemblies with extraordinary structural and functional sophistication. Taking lessons from biological assemblies, the recent integration of molecular design and synthesis with noncovalent forces such as hydrogenbonding, electrostatic, hydrophobic, π − π and ion-π interactions, along with metal-organic architectures and covalent capture of supramolecular assemblies, has made a significant inroad towards producing various synthetic channels and pores, either from organic building blocks or from cyclic peptides [5][6][7][8][9][10][11][12][13] . Many of these synthetic molecular and supramolecular structures exhibit interesting masstransporting properties.…”

Self-assembled graphitic nanotubes with one-handed helical arrays of a chiral amphiphilic molecular graphene

“…The prominent functions of these biological components have motivated chemists to design artificial helical architectures (1)(2)(3)(4)(5)(6)(7)(8), which can be used for a variety of applications such as chiral separation (9,10) and sensing (11)(12)(13)(14)(15), asymmetric synthesis (16), liquid crystals (17)(18)(19), nonlinear optics (20,21), and so forth. Recently, a hot issue of chirality has emerged in relation to the helicity of the hexagonal carbon lattice in carbon nanotubes, because it determines the conductive properties of carbon nanotubes (22)(23)(24).…”

Self‐Assembly of Amphiphilic Janus Dendrimers into Mechanically Robust Supramolecular Hydrogels for Sustained Drug Release

“…[4,5] Dendritic gels rely on well-defined, sequentially branched polymers (dendrimers) to form nanoscale networks. Dendrimers with various architectures and topologies offer a high number of functional surface groups which can be tailored to enhance binding affinity or material structure properties, [6][7][8][9][10][11][12] mediate the formation of hierarchically ordered assemblies and other complex systems, [13,14] transfer and amplify chirality, [15,16] facilitate the formation of crystalline complexes, [8] serve as powerful structuredirecting tectons [17] and as "supramolecular glue". [18,19] Dendritic gels rely on well-defined, sequentially branched polymers (dendrimers) to form nanoscale networks.…”