Co-immobilization of LAAO and Pt NPs in HOFs: An enzyme-metal coupled catalysis for enhancing the one-pot synthesis of α-keto acid

The enzymatic oxidation of amino acids using amino acid oxidases (AAOs) as biocatalysts for α-keto acid synthesis has garnered increasing attention due to its environmental friendliness and exceptional reaction efficiency. However, the by-product H 2 O 2 inevitably causes the decarboxylation of α-keto acids and subsequently deactivates the enzyme. Herein, we used a simple in-situ biomineralization method to immobilize Pt NPs with catalase-like activity and L-amino acid oxidase (LAAO) in to a hydrogen-bonded organic framework ( TW HOF) under a mild condition, and the synthesized LAAO-Pt@ TW HOF cascade catalytic system was applied to synthesis of α-keto acid. Compared with free LAAO, the LAAO-Pt@ TW HOF exhibited a 3.3-fold activity, well reusability and complete conversion (100 %) of L-tryptophan to indole-3-pyruvic acid was achieved. This work offers a potential application of HOF materials in constructing high-efficiency enzyme-metal coupled catalyst for cascade reactions.