Baeyer–Villiger monooxygenases: Recent advances and future challenges

Laboratory of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Current opinion in chemical biology (Impact Factor: 6.81). 12/2009; 14(2):138-44. DOI: 10.1016/j.cbpa.2009.11.017
Source: PubMed


Baeyer-Villiger monooxygenases For many enzyme classes, a wealth of information on, for example, structure and mechanism has been generated in the last few decades. While the first Baeyer-Villiger monooxygenases (BVMOs) were already isolated more than 30 years ago, detailed data on these enzymes were lacking until recently. Over the last years several major scientific breakthroughs, including the elucidation of BVMO crystal structures and the identification of numerous novel BVMOs, have boosted the research on BVMOs. This has led to intensified biocatalytic explorations of novel BVMOs and structure-inspired enzyme redesign. This review provides an overview on the recently gained knowledge on BVMOs and sketches the outlook for future industrial applications of these unique oxidative biocatalysts.

Download full-text


Available from: Marco W Fraaije
    • "In the last decade, the toolbox of flavoenzymes has significantly expanded thanks to enzyme engineering and discovery efforts [8] [9] [10]. The majority of flavoenzymes contain a tightly and non-covalently bound FAD cofactor. "
    [Show abstract] [Hide abstract]
    ABSTRACT: A generic approach for flavoenzyme immobilization was developed in which the flavin cofactor is used for anchoring enzymes onto the carrier. It exploits the tight binding of flavin cofactors to their target apo proteins. The method was tested for phenylacetone monooxygenase (PAMO) which is a well-studied and industrially interesting biocatalyst. Also a fusion protein was tested: PAMO fused to phosphite dehydrogenase (PTDH-PAMO). The employed flavin cofactor derivative, N6-(6-carboxyhexyl)-FAD succinimidylester (FAD*), was covalently anchored to agarose beads and served for apo enzyme immobilization by their reconstitution into holo enzymes. The thus immobilized enzymes retained their activity and remained active after several rounds of catalysis. For both tested enzymes, the generated agarose beads contained 3 U per g of dry resin. Notably, FAD-immobilized PAMO was found to be more thermostable (40% activity after 1. h at 60. °C) when compared to PAMO in solution (no activity detected after 1. h at 60. °C). The FAD-decorated agarose material could be easily recycled allowing multiple rounds of immobilization. This method allows an efficient and selective immobilization of flavoproteins via the FAD flavin cofactor onto a recyclable carrier.
    No preview · Article · Sep 2015 · Enzyme and Microbial Technology
  • Source
    • "c o m / l o c a t e / c e j the biocatalyzer (whole cells) in the aqueous phase [4], a stirred tank partitioning bioreactor using ionic liquids as the dispersed phase [10] and CHMO molecular structure changes to fold the serines susceptible to oxidation inside the enzyme [11]. Despite several experimental studies on the molecular structure of CHMO, its catalytic activity and reaction rates of the intermediate steps in the overall reaction in order to propose a basic bioconversion mechanism [12] [13] [14], there have been few studies on kinetic modeling considering simultaneous substrate, product and oxygen inhibition phenomena. Some pseudo empirical kinetic models have been reported following Michaelis–Menten approach to describe product formation and substrate consumption in monooxygenase kinetics [15] [16] [17]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of the current work was to develop a pseudo intrinsic kinetic model, based on elementary reactions, to describe the behavior of the bioconversion of ketones using Escherichia coli TOP10 pQR239. Since there are no reports of the oxygen inactivation constant in the literature, this study gave new insights to find optimal conditions of a suitable oxygen supply during the bioconversion. In this model the reaction mechanism proposed followed the formalism of Langmuir–Hinshelwood and considered both substrate inhibition and oxygen inactivation by the formation of intermediary complexes. Therefore, approximations of the pseudo equilibrium of reaction rates or steady state intermediary species were not considered, which allowed for identifying the role of each reaction step involved in the bioconversion. This kinetic model adequately described the observations with and without substrate inhibition and/or oxygen inactivation. And the regression and the estimated parameters were statistically significant, making these analyses reliable regarding the kinetic behavior of CHMO. Then, substrate and oxygen affinity and inhibition constants were obtained from the kinetic parameters of the model. It was observed that oxygen and substrate presented similar affinity constant values. The substrate inhibition (KIS) and oxygen inactivation (KIO2) constants were determined to be 9.98 μM and 22.3 μM, respectively, showing that the CHMO enzyme was twice more sensitive to inhibition by an excess of substrate than oxygen.
    Full-text · Article · Mar 2014 · The Chemical Engineering Journal
  • Source
    • "The target enzyme, CHMO, can be considered as the prototype enzyme for Baeyer–Villiger monooxygenases (BVMOs), an enzyme class that is attracting an ever-increasing interest for being applied in biocatalytic processes [14] [15] [16] [17] [18] [19] [20]. CHMO has been studied for its biocatalytic potential in numerous studies which has revealed that it (1) accepts a wide range of aliphatic substrates, (2) is able to perform chemo-and regioselective oxidations, and (3) yields absolute enantioselectivity for many of the tested conversions [19] [21]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Enzyme stability is an important parameter in biocatalytic applications, and there is a strong need for efficient methods to generate robust enzymes. We investigated whether stabilizing disulfide bonds can be computationally designed based on a model structure. In our approach, unlike in previous disulfide engineering studies, short bonds spanning only a few residues were included. We used cyclohexanone monooxygenase (CHMO), a Baeyer-Villiger monooxygenase (BVMO) from Acinetobacter sp. NCIMB9871 as the target enzyme. This enzyme has been the prototype BVMO for many biocatalytic studies even though it is notoriously labile. After creating a small library of mutant enzymes with introduced cysteine pairs and subsequent screening for improved thermostability, three stabilizing disulfide bonds were identified. The introduced disulfide bonds are all within 12 Å of each other, suggesting this particular region is critical for unfolding. This study shows that stabilizing disulfide bonds do not have to span many residues, as the most stabilizing disulfide bond, L323C-A325C, spans only one residue while it stabilizes the enzyme, as shown by a 6 °C increase in its apparent melting temperature.
    Full-text · Article · Feb 2014 · FEBS Open Bio
Show more