Artificial metalloenzymes (ArMs) aim to combine the reaction scope of synthetic catalysts with the selectivity and biocompatibility of proteins. We have developed an iron-binding siderophore anchor to connect synthetic catalysts to siderophore-binding proteins, thereby creating artificial transfer hydrogenases. In the presence of Fe(III), the siderophore-based anchor binds with high affinity, but on reduction to Fe(II), dissociation takes place and the ArM disassembles, allowing the protein scaffold to be reclaimed and recycled.1
This siderophore-based reversible ‘catch-and-release’ approach not only allows the recharging of catalysts that have lost activity, for example due to poisoning or decomposition, but also enables catalysts to be exchanged, as demonstrated by enantioselectivity switching in cross linked ArM aggregates (figure 1).2
The immobilisation of siderophore-anchored ArMs on solid supports and the use of redox-control and flow techniques to direct ArM assembly provides new opportunities for biocatalysis, in particular component recycling and incorporation into flow processes.3
Figure 1.