Design of De Novo Three-Enzyme Nanoreactors for Stereodivergent Synthesis of α-Substituted Cyclohexanols

Abstract

Emulating nature to design multienzyme cascade systems for the given synthetic targets is fascinating but highly challenging. Here, we established a three-enzyme nanoreactor (TENR) for stereodivergent synthesis of α-substituted cyclohexanols, in which the two contiguous chiral centers are created by old yellow enzyme (OYE)- and alcohol dehydrogenase (ADH)-catalyzed asymmetric reductions, coupled with glucose dehydrogenase (GDH)-catalyzed cofactor regeneration. To achieve this goal, enantio-complementary OYEs and ADHs were identified, in which an (S)-stereoselective OYE variant toward α-methyl cyclohexenone was obtained by site-directed mutagenesis based on the rational enzyme design. The TENR with high compositional and spatial controls was fabricated by coimmobilizing the three enzymes on amphiphilic core–shell polydopamine-encapsulated dendritic organosilica nanoparticles. A customized microenvironment for the rate-limiting enzyme and the rationally arranged locations of enzymes that match the reaction sequence was designed to improve the cascade catalytic performance. Moreover, the TENR displayed much higher stability, reusability, and cofactor recycling efficiency than that of the free multienzyme system.

Application of Immobilized Enzymes in Flow Biocatalysis for Efficient Synthesis

“…In 2023, they released a continuous-flow cascade system for enantioselective synthesis of chiral α-monoand difluoromethyl amines (Figure 22). 113 This system was composed of two catalytic modules. The β-ketoacid esters were hydrolyzed by immobilized CALB (CALB@ nanoflowers) and then converted to mono-or difluoromethyl penyl ketone by Selectfluor, a fluorinating reagent, through decarboxylative fluorination.…”

Co-Immobilization of Enzymes and Metals on the Covalent-Organic Framework for the Efficient Removal of Mycotoxins

“…For example, the chemoenzymatic cascade reaction catalyzed by GOx and Fe 3 O 4 NPs. , In this process, GOx catalyzes the oxidation of glucose to produce gluconic acid and H 2 O 2 , which then transforms into the OH • radical through the Fenton reaction catalyzed by Fe 3 O 4 NPs. However, the construction of enzyme-metal hybrid catalysts with high activity and stability for the one-pot chemoenzymatic cascade reaction remains a challenge. − …”

Rhodium-Based MOF-on-MOF Difunctional Core–Shell Nanoreactor for NAD(P)H Regeneration and Enzyme Directed Immobilization

“…Significant progress has been made in integrating oxidoreductase into an artificial catalytic system to efficiently drive a series of complex bio-transformations with sustainable feedstocks. This process often requires the participation of coenzymes, particularly NAD(P)H. − Restricted by the high cost and bioavailability of coenzymes, it is of great significance to develop strategies for efficient regeneration of coenzymes NAD(P)H. Currently, various methods for the reduction of NAD(P) + to NAD(P)H, such as enzymatic, , photochemical, − and electrochemical methods, − have been extensively studied. Among them, organometallic complexes {such as [Cp*Rh(bpy)Cl]Cl} have flexible chemical regeneration ability, regiospecific performance, and high catalytic properties for NAD(P)H regeneration. − In the catalytic process, Rh serves as the electron/proton mediator to store electrons for NAD(P)H regeneration .…”