Assessing the Substrate Selectivities and Enantioselectivities of Eight Novel Baeyer−Villiger Monooxygenases toward Alkyl-Substituted Cyclohexanones
作者:Brian G. Kyte、Pierre Rouvière、Qiong Cheng、Jon D. Stewart
DOI:10.1021/jo030253l
日期:2004.1.1
4-alkyl-substituted cyclohexanones tested, enzymes were discovered that afforded each of the corresponding (S)-lactones in ≥98% ee. This was also true for the 2-alkyl-substituted cyclohexanones examined. The situation was more complex for 3-akyl-substituted cyclohexanones. In a few cases, single Baeyer−Villiger monooxygenases possessed both high regio- and enantioselectivities toward these compounds
Manipulating the stereoselectivity of the thermostable Baeyer–Villiger monooxygenase TmCHMO by directed evolution
作者:Guangyue Li、Maximilian J. L. J. Fürst、Hamid Reza Mansouri、Anna K. Ressmann、Adriana Ilie、Florian Rudroff、Marko D. Mihovilovic、Marco W. Fraaije、Manfred T. Reetz
DOI:10.1039/c7ob02692g
日期:——
oxidation of a variety of structurally different ketones with notable activity and enantioselectivity, including the desymmetrization of 4-methylcyclohexanone (99% ee, S). In order to induce the reversal of enantioselectivity of this reaction as well as the transformations of other substrates, directedevolution based on iterative saturationmutagenesis (ISM) was applied, leading to (R)-selectivity (94%
Broadening the scope of Baeyer–Villiger monooxygenase activities toward α,β-unsaturated ketones: a promising route to chiral enol-lactones and ene-lactones
作者:T. Reignier、V. de Berardinis、J.-L. Petit、A. Mariage、K. Hamzé、K. Duquesne、V. Alphand
DOI:10.1039/c4cc02541e
日期:——
Three regiodivergent BaeyerâVilliger mono-oxygenases (enantioselectively) oxidized a series of cyclic α,β-unsaturated ketones into (chiral) either enol-lactones or ene-lactones. An easy-to-use and efficient biocatalytic process based on a host-microorganism deprived of unwanted activities (knock-out mutant) was developed to enable the exclusive synthesis of unsaturated lactones.
Asymmetric Baeyer–Villiger oxidation: classical and parallel kinetic resolution of 3-substituted cyclohexanones and desymmetrization of <i>meso</i>-disubstituted cycloketones
Regioselectivity is a crucial issue in Baeyer–Villiger (BV) oxidation. To date, few reports have addressed asymmetric BV oxidation of 3-substituted cycloketones due to the high difficulty of controlling regio- and stereoselectivity. Herein, we report the asymmetric BV oxidation of 3-substituted and meso-disubstituted cycloketones with chiral N,N′-dioxide/Sc(III) catalysts performed in three ways: classical
Crystal Structures of Cyclohexanone Monooxygenase Reveal Complex Domain Movements and a Sliding Cofactor
作者:I. Ahmad Mirza、Brahm J. Yachnin、Shaozhao Wang、Stephan Grosse、Hélène Bergeron、Akihiro Imura、Hiroaki Iwaki、Yoshie Hasegawa、Peter C. K. Lau、Albert M. Berghuis
DOI:10.1021/ja9010578
日期:2009.7.1
Cyclohexanone monooxygenase (CHMO) is a flavoprotein that carries out the archetypical Baeyer-Villiger oxidation of a variety of cyclic ketones into lactones. Using NADPH and O-2 as cosubstrates, the enzyme inserts one atom of oxygen into the substrate in a complex catalytic mechanism that involves the formation of a flavin-peroxide and Criegee intermediate. We present here the atomic structures of CHMO from an environmental Rhodococcus strain bound with FAD and NADP(+) in two distinct states, to resolutions of 2.3 and 2.2 angstrom. The two conformations reveal domain shifts around multiple linkers and loop movements, involving conserved arginine 329 and tryptophan 492, which effect a translation of the nicotinamide resulting in a sliding cofactor. Consequently, the cofactor is ideally situated and subsequently repositioned during the catalytic cycle to first reduce the flavin and later stabilize formation of the Criegee intermediate. Concurrent movements of a loop adjacent to the active site demonstrate how this protein can effect large changes in the size and shape of the substrate binding pocket to accommodate a diverse range of substrates. Finally, the previously identified BVMO signature sequence is highlighted for its role in coordinating domain movements. Taken together, these structures provide mechanistic insights into CHMO-catalyzed Baeyer-Villiger oxidation.