Enhanced diastereoselective synthesis of t‐Butyl 6‐cyano‐(3R, 5R)‐dihydroxyhexanoate by using aldo‐keto reductase and glucose dehydrogenase co‐producing engineered Escherichia coli. (6th September 2017)

• Record Type: Journal Article
• Authors: Wang, Ya‐Jun; Shen, Wei; Luo, Xi; Liu, Zhi‐Qiang; Zheng, Yu‐Guo
• Is Part Of: Biotechnology progress. Volume 33:Number 5(2017)
• Page Start: 1235
• Page End: 1242
• Publication Date: 2017-09-06
• Subjects: t‐butyl 6‐cyano‐(3R, 5R)‐dihydroxyhexanoate -- aldo‐keto reductase -- co‐expression -- asymmetric reduction; Biotechnology -- Periodicals; Food industry and trade -- Periodicals; Bioengineering -- Periodicals; 660.6
• DOI: 10.1002/btpr.2543
• Languages: English
• ISSNs: 8756-7938

Abstract

Abstract : t ‐Butyl 6‐cyano‐(3 R, 5 R )‐dihydroxyhexanoate ((3 R, 5 R )‐2 ) is a key chiral diol precursor of atorvastatin calcium (Lipitor®). We have constructed a Kluyveromyces lactis aldo‐keto reductase mutant Kl AKR‐Y295W/W296L ( Kl AKRm) by rational design in previous research, which displayed high activity and excellent diastereoselectivity ( de p > 99.5%) toward t ‐butyl 6‐cyano‐(5 R )‐hydroxy‐3‐oxohexanoate ((5 R )‐1 ). To realize in situ cofactor regeneration, a robust Kl AKRm and Exiguobacterium sibiricum glucose dehydrogenase ( Es GDH) co‐producer E. coli BL 21(DE3) pETDuet‐ esgdh (MCS1)/pET‐28b (+)‐ klakrm was constructed in this work. Under the optimized conditions, AKR and GDH activities of E. coli BL 21(DE3) pETDuet‐ esgdh (MCS1)/pET‐28b (+)‐ klakrm peaked at 249.9 U/g DCW (dry cellular weight) and 29100 U/g DCW, respectively. It completely converted (5 R )‐1 at substrate loading size of up to 60.0 g/L (5 R )‐1 in the absence of exogenous NADH, which was one‐fifth higher than that of the separately prepared Kl AKRm and Es GDH under the same conditions. In this manner, a biocatalytic process for (3 R, 5 R )‐2 with productivity of 243.2 kg/m 3 d was developed. Compared with the combination of separate expressed Kl AKRm with Es GDH, co‐expression of Kl AKRm and Es GDH has the advantages of alleviating cell cultivation burden and elevating substrate load. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1235–1242, 2017