LAUSR

Methane monooxygenase (MMO), which exists in particulate (pMMO) or soluble forms (sMMO) in methanotrophic bacteria, is an industrially promising enzyme that catalyses oxidation of low-reactive methane and other carbon feedstocks into methanol and their corresponding oxidation products. However, the simple, fast and high-yield production of functionally active MMO, which has so far been unsuccessful despite diverse approaches based on either native methanotroph culture or recombinant expression systems, remains a major challenge for its industrial applications. Here we developed pMMO-mimetic catalytic protein constructs by genetically encoding the beneficial reassembly of catalytic domains of pMMO on apoferritin as a biosynthetic scaffold. This approach resulted in high-yield synthesis of stable and soluble protein constructs in Escherichia coli, which successfully retain enzymatic activity for methanol production with a turnover number comparable to that of native pMMO.Methane monooxygenase (MMO)—a protein of high biotechnological interest for the selective and mild conversion of methane to methanol—lacks a high-throughput production system. Now, the authors report the efficient production of particulate MMO-mimics for catalysis in solution and hydrogels.