Self-assembly of amphiphilic dendritic dipeptides into helical pores

Abstract

Natural pore-forming proteins act as viral helical coats¹ and transmembrane channels^2,3,4, exhibit antibacterial activity⁵ and are used in synthetic systems, such as for reversible encapsulation⁶ or stochastic sensing⁷. These diverse functions are intimately linked to protein structure^1,2,3,4. 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^8,9, synthetic pore structures capable of assembling into periodically ordered assemblies that are stable in solution and in the solid state^10,11,12,13 have not yet been realized. In the case of dendrimers, covalent¹⁴ and non-covalent¹⁵ coating and assembly of a range of different structures^15,16,17 has only yielded closed columns¹⁸. 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.