Supramolecular approaches to combining established natural enzymes with artificial catalysts have become a vital form to achieve efficient and selective catalytic conversions in a bio-orthogonal way.1 The construction of disparate abiological functional groups within the active domain of enzymes in bioinorganic hybrid systems is becoming a highly promising route toward unusual catalytic results immersed in one-pot intricate catalytic networks. As the metal-organic capsules with decorated cofactors enable the efficient proton/electron transfer between the inner and outer spaces of the microenvironment without the cofactor shuttling,2 we envisioned that a supramolecular approach that included the cofactors (i.e., NADH and FAD) and its mimics into the surface of a catalyst-functionalized assembly would be a new approach to combine multiple individual active sites into catalytic pockets of enzymes, enabling biological cascades by merging abiotic catalysis with cofactor-dependent enzymatic reactions in one working module.3 By installing both NADH and heme analogues into a flavin model contained heteroleptic metal-organic rectangle, such cytochrome P450 oxygenase analogue could efficiently catalytic oxidative cascade in tandem with dehydrogenases.4 By grafting a cage-dye-NADH clathrate clathrate with glucose dehydrogenase (GDH), a consecutive photoinduced electron-transfer approach to reform biomass into fuels and active H-source for nitroarene reduction was achieved (Figure 1). The grafting enzyme combines artificial photocatalysis and enzymatic dehydrogenation to innovate a unique paradigm for the sustainable energy scheme that combines energy of two photons in one turnover cycle.5 The host-guest approach to simultaneously introduce virous functional groups into different enzymes paves a way for the application of bio-inorganic systems in bionic catalysis.
Figure 1. Construction of bio-inorganic systems containing metal-organic capsules binding with enzymes.