Chantel N Jensen

Publications (2)7.88 Total impact

• Source

  Available from: Jozef I Nissimov

  Article: Genome sequence of Stenotrophomonas maltophilia PML168, which displays Baeyer-Villiger monooxygenase activity.

  Michael J Allen, Karen Tait, Martin Mühling, Karen Weynberg, Claire Bradley, Urmi Trivedi, Karim Gharbi, Jozef Nissimov, Konstantinos Mavromatis, Chantel N Jensen, Gideon Grogan, Sohail T Ali
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  ABSTRACT: Stenotrophomonas maltophilia PML168 was isolated from Wembury Beach on the English Coast from a rock pool following growth and selection on agar plates. Here we present the permanent draft genome sequence, which has allowed prediction of function for several genes encoding enzymes relevant to industrial biotechnology, including a novel flavoprotein monooxygenase.
  Journal of bacteriology 09/2012; 194(17):4753-4. · 3.94 Impact Factor
• Article: A flavoprotein monooxygenase that catalyses a Baeyer-Villiger reaction and thioether oxidation using NADH as the nicotinamide cofactor.

  Chantel N Jensen, Jared Cartwright, Jonathan Ward, Sam Hart, Johan P Turkenburg, Sohail T Ali, Michael J Allen, Gideon Grogan
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  ABSTRACT: A gene from the marine bacterium Stenotrophomonas maltophilia encodes a 38.6 kDa FAD-containing flavoprotein (Uniprot B2FLR2) named S. maltophilia flavin-containing monooxygenase (SMFMO), which catalyses the oxidation of thioethers and also the regioselective Baeyer-Villiger oxidation of the model substrate bicyclo[3.2.0]hept-2-en-6-one. The enzyme was unusual in its ability to employ either NADH or NADPH as nicotinamide cofactor. The K(M) and k(cat) values for NADH were 23.7±9.1 μM and 0.029 s(-1) and 27.3±5.3 μM and 0.022 s(-1) for NADPH. However, k(cat) /K(M) value for the ketone substrate in the presence of 100 μM cofactor was 17 times greater for NADH than for NADPH. SMFMO catalysed the quantitative conversion of 5 mM ketone in the presence of substoichiometric concentrations of NADH with the formate dehydrogenase cofactor recycling system, to give the 2-oxa and 3-oxa lactone products of Baeyer-Villiger reaction in a ratio of 5:1, albeit with poor enantioselectivity. The conversion with NADPH was 15 %. SMFMO also catalysed the NADH-dependent transformation of prochiral aromatic thioethers, giving in the best case, 80 % ee for the transformation of p-chlorophenyl methyl sulfide to its R enantiomer. The structure of SMFMO reveals that the relaxation in cofactor specificity appears to be accomplished by the substitution of an arginine residue, responsible for recognition of the 2'-phosphate on the NADPH ribose in related NADPH-dependent FMOs, with a glutamine residue in SMFMO. SMFMO is thus representative of a separate class of single-component, flavoprotein monooxygenases that catalyse NADH-dependent oxidations from which possible sequences and strategies for developing NADH-dependent biocatalysts for asymmetric oxygenation reactions might be identified.
  ChemBioChem 03/2012; 13(6):872-8. · 3.94 Impact Factor