Discovery, Characterization, Engineering, and Applications of Ene-Reductases for Industrial Biocatalysis

Abstract

Recent studies of multiple enzyme families collectively referred to as ene-reductases (ERs) have highlighted potential industrial application of these biocatalysts in the production of fine and speciality chemicals. Processes have been developed whereby ERs contribute to synthetic routes as isolated enzymes, components of multi-enzyme cascades, and more recently in metabolic engineering and synthetic biology programmes using microbial cell factories to support chemicals production. The discovery of ERs from previously untapped sources and the expansion of directed evolution screening programmes, coupled to deeper mechanistic understanding of ER reactions, have driven their use in natural product and chemicals synthesis. Here we review developments, challenges and opportunities for the use of ERs in fine and speciality chemicals manufacture. The ER research field is rapidly expanding and the focus of this review is on developments that have emerged predominantly over the last 4 years.

Synthesis and Biochemical Evaluation of Nicotinamide Derivatives as NADH Analogue Coenzymes in Ene Reductase

“…ER‐catalyzed reactions in the absence of NADH analogues served as negative controls, and thus it was decided to investigate these reactions further by employing our synthetic derivatives as NADH analogues. Research into NADH‐dependent alkene reduction catalyzed by these enzymes has been described in respect to their applications in industrial processes . ER also exhibits cofactor promiscuity and has been reported to accept a wide range of substrates; this emphasizes its versatility and the expansion of its use .…”

“…Research into NADH‐dependent alkene reduction catalyzed by these enzymes has been described in respect to their applications in industrial processes . ER also exhibits cofactor promiscuity and has been reported to accept a wide range of substrates; this emphasizes its versatility and the expansion of its use . Therefore, our synthesized NADH analogues were evaluated in an ER for which clear controls had previously been run prior and precise results had been drawn.…”

Stereodivergent Synthesis of Carveol and Dihydrocarveol through Ketoreductases/Ene‐Reductases Catalyzed Asymmetric Reduction

“…The biocatalytic reduction of activated C=C bond of carvone ( 1 ) to give dihydrocarvone ( 3 ) has been well studied by several ene‐reductases ,,,. For example, (1 R ,4 R )‐ 3 and (1 R ,4 S )‐ 3 could be obtained through asymmetric reduction of corresponding (4 R )‐ 1 and (4 S )‐ 1 by various ene‐reductases, such as OYE1,, PETNR, and so on . However, only a few ene‐reductase variants, such as OYEW116A/V and TsER C25G/I67T, displayed switched stereoselectivity to yield dihydrocarvone with S configuration at C‐1 position.…”

Biocatalysis Fueled by Light: On the Versatile Combination of Photocatalysis and Enzymes

“…Another relevant enzyme class for photo‐biocatalysis is that of ene reductases (ERs). These NAD(P)H‐dependent enzymes catalyze the alkene reduction of (prochiral) double bonds, thereby enabling the generation of up to two stereogenic centers at a time with high enantioselectivity . The FMN‐containing ER subclass of Old Yellow Enzymes (OYEs) displays a broad substrate range.…”

“…These NAD(P)H-dependent enzymes catalyzet he alkene reduction of (prochiral) double bonds, thereby enabling the generation of up to two stereogenic centers at at ime with high enantioselectivity. [31] The FMN-containing ER subclass of Old Yellow Enzymes (OYEs) [32] displays a broad substrate range. Within these class, ah ydride is transferred in aM ichael-typep rocess from the reduced flavin 15 to the C=Cdouble bond (Scheme 5E).…”