Building From Biology – Peptides as Building Blocks in Supramolecular Chemistry

Advances in metal-organic cage self-assembly have enabled the construction of increasingly complex, discrete three-dimensional architectures reminiscent of proteins from simple building blocks. The current state-of-the-art, however, is almost exclusively built from rigid and flat aromatic panels, limiting binding selectivity and, often, water solubility.I’ll talk about some of my work creating less symmetric metal-organic cages, then about some work from my research group, creating a new class of cages – metal-peptidic cages – which utilise water-soluble, chiral and helical oligoproline strands of varying length to generate highly anisotropic nanospaces. We demonstrate the assembly of a range of Pd2L4 cages, with lengths from c. 1 – 4 nm, and find formation of the cis isomer of the cage is strongly favoured – an emergent property of using complex and chiral building blocks in the formation of defined nanospaces. Further, the use of biologically relevant components enables targeted binding of therapeutic molecules, highlighting the potential of these systems for selective drug delivery. Finally, I’ll explore some recent, unexpected, results as we have further explored metal-peptidic cage synthesis. Challenge to be solved – wholesale migration of synthetic supramolecular chemistry to operate in water!