We have created a chemoenzymatic technology for macrocycle generation
The technology consists of a set of flexible engineered enzymes which can carry out modification steps on a synthetic linear substrate to generate modified macrocycles. We have used our knowledge of the structures and mechanisms of the individual enzymes of a number of cyanobactin biosynthesis pathways to engineer them so that they can be used for fast, cost-effective synthesis of a range of modified macrocycles from exogenously-supplied linear peptide substrates.
An example of a modified heterocyclase which can fully process short leader-less peptides has been published: “Structural analysis of leader peptide binding enables leader-free cyanobactin processing”, Jesko Koehnke et al., Nature ChemBiol, 2015, 11, 558
We have broadened the substrate specificity of the biosynthetic enzymes, as well as removing the need for a large N-terminal recognition sequence (leader) in the substrate peptide. The substrate can be 6-12 residues in length, and may contain L- and/or D-amino acids and residues with non-natural side groups. The engineered enzymes can already be produced at gram scale and work at appreciable rates so that the entire chemoenzymatic process is complete in 1-2 days, excluding purification. The final macrocycle can be produced at multi-milligram scale with larger scales possible.