Gas-phase enzymatic catalysis has been long pursued but not yet utilized in industrial processes due to many limitations. Herein, we report a hydroxyl-rich graphene oxide (GO) aerogel that can preserve the enzymatic activity and stability in an anhydrous gas flow by providing a water-like microenvironment. Lipase immobilized in the GO aerogel exhibits a 5 to 10-fold increase in apparent activity than the lyophilized lipase powder in transesterification of geraniol and vinyl acetate in the gas phase and maintains the initial activity for more than 500 h. The solid-state circular dichroism measurement confirms that the lipase keeps its native conformation in the aerogel, and the thermogravimetric analysis shows that water molecules essential for the lipase activity can be replaced by the hydroxyl groups at the GO surface. The versatility of this method is demonstrated for two other lipases with different structures, promising unprecedented applications of enzyme-GO aerogels to gas-phase enzymatic catalysis.

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A perennial interest in enzyme catalysis has been expanding its applicability from aqueous phase where enzymes are naturally evolved to organic solvents in which the majority of industrial chemical synthesis...

As a basic feedstock for both natural life and chemical production, glucose is converted into various chemicals upon the help of peroxidase cascades composed of glucose oxidase (GOx) and peroxidases. However, little is known about the glucose effect on the structure and activity of peroxidases in a non-natural environment. We report herein that glucose deactivates chloroperoxidase (CPO) used in the asymmetric hydroxylation of ethylbenzene into (R)-1-phenylethanol. Through both experiment and molecular simulation, we discover that glucose deactivates CPO through hydrophobic interaction with heme and hydrogen bonding with Glu 183 . These interactions lead to heme leakage and the reduction of H 2 O 2 uptake thereby undermining the CPO activity. The mechanism appears generically applicable to other hemeproteins such as horseradish peroxidase, hemoglobin, and myoglobin. These findings may open new avenues for the design of peroxidase cascades for applications ranging from better diagnosis of diabetes to green synthesis of chemicals by direct functionalization of CÀ H bonds.