TY - JOUR
T1 - Exploring DES-Water Mixtures for Improved ADH-CHMO Fusion Enzyme Performance in Linear Cascades
AU - Ma, Yu
AU - Vernet, Guillem
AU - Zhang, Ningning
AU - Kara, Selin
N1 - Publisher Copyright:
© 2024 Wiley-VCH GmbH.
PY - 2025/3/6
Y1 - 2025/3/6
N2 - The application of multienzyme cascade reactions in nonaqueous media has garnered attention due to their potential in Green Chemistry. Deep eutectic solvents (DESs) have emerged as a novel alternative with high tunability. This study investigated the use of fusion enzymes, combining an alcohol dehydrogenase (ADH) and a cyclohexanone monooxygenase (CHMO), for a linear cascade stepwise oxidation of cyclohexanol to ɛ-caprolactone with in situ cofactor regeneration in DES-water mixtures. The stability of fusion enzymes was determined in the two DESs comprising glycerol and betaine or choline acetate at the same molar ratio (Bet–Gly, ChAc–Gly, 1:2) with various water contents (20–80 vol.%), as well as in pure buffer for comparison. Bet–Gly significantly improved enzyme thermostability at ≥40 vol.% water and doubled the half-life time of CHMO, whereas ChAc–Gly showed a deleterious effect. The improved thermostability promoted the further optimization of the cascade reaction while addressing the high viscosity of DESs through increasing water ratios and temperatures. The reaction efficiency in DES-buffer mixtures was comparable to the pure buffer system (97.0% yield in 24 h), while product hydrolysis was completely avoided. High substrate loadings (8 g/L cyclohexanol) and extended substrate ranges were accomplished. These findings highlight the potential of DES-enriched media to improve catalytic efficiency and further advance sustainable biocatalytic processes.
AB - The application of multienzyme cascade reactions in nonaqueous media has garnered attention due to their potential in Green Chemistry. Deep eutectic solvents (DESs) have emerged as a novel alternative with high tunability. This study investigated the use of fusion enzymes, combining an alcohol dehydrogenase (ADH) and a cyclohexanone monooxygenase (CHMO), for a linear cascade stepwise oxidation of cyclohexanol to ɛ-caprolactone with in situ cofactor regeneration in DES-water mixtures. The stability of fusion enzymes was determined in the two DESs comprising glycerol and betaine or choline acetate at the same molar ratio (Bet–Gly, ChAc–Gly, 1:2) with various water contents (20–80 vol.%), as well as in pure buffer for comparison. Bet–Gly significantly improved enzyme thermostability at ≥40 vol.% water and doubled the half-life time of CHMO, whereas ChAc–Gly showed a deleterious effect. The improved thermostability promoted the further optimization of the cascade reaction while addressing the high viscosity of DESs through increasing water ratios and temperatures. The reaction efficiency in DES-buffer mixtures was comparable to the pure buffer system (97.0% yield in 24 h), while product hydrolysis was completely avoided. High substrate loadings (8 g/L cyclohexanol) and extended substrate ranges were accomplished. These findings highlight the potential of DES-enriched media to improve catalytic efficiency and further advance sustainable biocatalytic processes.
KW - Cyclohexanone monooxygenase
KW - Deep eutectic solvents
KW - Enzymatic lactonizations
KW - Fusion enzyme
KW - Oxyfunctionalizations
UR - http://www.scopus.com/inward/record.url?scp=86000377935&partnerID=8YFLogxK
U2 - 10.1002/cctc.202401792
DO - 10.1002/cctc.202401792
M3 - Journal article
AN - SCOPUS:86000377935
SN - 1867-3880
VL - 17
JO - ChemCatChem
JF - ChemCatChem
IS - 5
M1 - e202401792
ER -