Semi-Rationally Designed Short Peptides Self-Assemble and Bind Hemin to Promote Cyclopropanation.

The self-assembly of short peptides gives rise to versatile nanoassemblies capable of promoting efficient catalysis. We have semi-rationally designed a series of seven-residue peptides that form hemin-binding catalytic amyloids to facilitate enantioselective cyclopropanation with efficiencies that rival those of engineered hemin proteins. These results demonstrate that: 1) Catalytic amyloids can bind complex metallocofactors to promote practically important multisubstrate transformations. 2) Even essentially flat surfaces of amyloid assemblies can impart a substantial degree of enantioselectivity without the need for extensive optimization. 3) The ease of peptide preparation allows for straightforward incorporation of unnatural amino acids and the preparation of peptides made from d-amino acids with complete reversal of enantioselectivity.