posted on 2021-10-12, 16:04authored byZhenfu Wang, Yang Liu, Xiaoyan Dong, Yan Sun
Chemoenzymatic
catalysis combining the traits of chemical and enzymatic
catalysis provides tremendous possibilities for the design of biosynthetic
pathways utilizing inorganic catalysts and enzymes. However, the efficiency
of chemoenzymatic catalysis is usually governed by the synergy and
compatibility of the two catalysts. Here, we report for the first
time the catalase-like activity of cobalt phosphate nanocrystals (CoPs).
By a one-pot biomimetic mineralization with CoPs and l-amino
acid oxidase (LAAO) under a mild condition, we have fabricated a hybrid
nanobiocatalyst, LAAO@CoPs, for the chemoenzymatic synthesis of α-keto
acid. The as-fabricated nanobiocatalyst with directly contacted catalytic
sites of the enzyme and nanozyme maximizes the substrate channeling
effects for in situ chemical decomposition of the oxidative intermediate,
H2O2, during the enzymatic oxidation of l-tryptophan (l-Trp), thus minimizing the H2O2 accumulation and byproduct generation. Benefiting from
the superiority of LAAO@CoPs, complete conversion (100.0%) of l-Trp to indole pyruvic acid is achieved, over two times higher
than the yield of the free LAAO system (47.6%). Meanwhile, LAAO@CoPs
show high stabilities against heat and proteolytic treatments. This
work offers a new design approach for constructing a high-performance
nanobiocatalyst for cascade reactions, especially for those systems
with toxic or reactive intermediates.