Spatiotemporal Encapsulation of Tandem Enzymes in Hierarchical Metal-Organic Frameworks for Cofactor-Dependent Photoenzymatic CO2 Conversion.

The photo-enzyme coupling system (PECS) holds immense potential in "green" biomanufacturing, encompassing the realms of pharmaceuticals, fuels, and carbon sequestration. Nevertheless, the intricate nature of enzymes' structures significantly impedes the seamless integration of multiple enzymes in a precise, tandem fashion, with exact control over their distribution, posing a formidable challenge. Herein, it has devised a mesoporous csq-type metal organic framework (Zr-MOF) from meso-tetrakis-(4-((phenyl)ethynyl)benzoate)porphyrin (Por-PTP) and Zr6(μ3-O)4(μ3-OH)4(OH)4(H2O)4) nodes (Zr6 clusters), featuring intricate hierarchical hexagonal (5.8 nm) and triangular (2.9 nm) channels, enabling the simultaneous encapsulation of Formate dehydrogenase from Candida boidinii (CbFDH) and ferredoxin-NADP+ reductase (FNR) via a spatiotemporally controlled strategy for cofactor-dependent photoenzymatic carbon dioxide (CO2) conversion. Upon illumination, photoexcited electrons originating from the Zr-MOF frameworks migrate to the adjacent FNR for cofactor NADH regeneration, which is then harnessed by proximal CbFDH for CO2 fixation. Concurrently, the resulting holes are neutralized by AA for system recovery. The results demonstrated the confinement of tandem enzymes within MOF channels significantly enhanced the performance of multi-enzyme cascade pathways as well as augmenting the local NAD+/NADH, which leading to a further improvement in the efficiency of tandem biocatalytic formic acid generation (55 mm) from CO2. Crucially, the photo-enzyme-coupled factories exhibited remarkable stability alongside exceptional recyclability, attributed to the preservation of MOF skeletons.