Divorce in the two-component BVMO family: the single oxygenase for enantioselective chemo-enzymatic Baeyer–Villiger oxidations. Issue 15 (26th March 2021)

• Record Type: Journal Article
• Authors: Röllig, Robert; Paul, Caroline E.; Claeys-Bruno, Magalie; Duquesne, Katia; Kara, Selin; Alphand, Véronique
• Is Part Of: Organic & biomolecular chemistry. Volume 19:Issue 15(2021)
• Page Start: 3441
• Page End: 3450
• Publication Date: 2021-03-26
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/d1ob00015b
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : The oxygenase part of a two-component BVMO in combination with synthetic nicotinamide analogues does not require any reductase or expensive NAD(P)H. Abstract : Two-component flavoprotein monooxygenases consist of a reductase and an oxygenase enzyme. The proof of functionality of the latter without its counterpart as well as the mechanism of flavin transfer remains unanswered beyond doubt. To tackle this question, we utilized a reductase-free reaction system applying purified 2, 5-diketocamphane-monooxygenase I (2, 5-DKCMO), a FMN-dependent type II Baeyer–Villiger monooxygenase, and synthetic nicotinamide analogues (NCBs) as dihydropyridine derivatives for FMN reduction. This system demonstrated the stand-alone quality of the oxygenase, as well as the mechanism of FMNH2 transport by free diffusion. The efficiency of this reductase-free system strongly relies on the balance of FMN reduction and enzymatic (re)oxidation, since reduced FMN in solution causes undesired side reactions, such as hydrogen peroxide formation. Design of experiments allowed us to (i) investigate the effect of various reaction parameters, underlining the importance to balance the FMN/FMNH2 cycle, (ii) optimize the reaction system for the enzymatic Baeyer–Villiger oxidation of r ac -bicyclo[3.2.0]hept-2-en-6-one, rac -camphor, and rac -norcamphor. Finally, this study not only demonstrates the reductase-independence of 2, 5-DKCMO, but also revisits the terminology of two-component flavoprotein monooxygenases for this specific case.