کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4752714 | 1416365 | 2017 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Fungal BVMOs as alternatives to cyclohexanone monooxygenase
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
FAD-dependent Baeyer-Villiger monooxygenases (BVMOs) have proven to be useful biocatalysts in the selective and specific oxygenation of various ketones. Despite the cloning, heterologous expression and characterization of close to 80 members of this enzyme family, some sub-groups of BVMOs still remain underrepresented and their evolutionary relationship uncertain. Until recently, very few fungal BVMOs have been described. Our previous investigations into BVMOs from the fungus Aspergillus flavus, yielded very little activity on simple cyclic ketones. Here we report on another four BVMOs from A. flavus that are more closely related to cyclohexanone monooxygenase (CHMO) from Acinetobacter sp. NCIMB 9871. Evolutionary analysis with other characterized BVMOs show their closest relationship to be with either cycloalkanone monooxygenase (CAMO) or 2-oxo-Î3-4,5,5-trimethylcyclopentenylacetyl-coenzyme A monooxygenase (OTEMO). The OTEMO-related BVMOAFL706 and BVMOAFL334 were heterologously expressed in E. coli, purified and shown to be able to convert a range of cyclic and substituted cyclic ketones. Of the unsubstituted cyclic ketones, cyclohexanone showed the highest conversion with maximum turnover frequencies reaching 4.3Â sâ1 for BVMOAFL706. Unlike CHMOacinet, and many of the closely related BVMOs, no substrate inhibition was observed with cyclohexanone to a concentration of up to 30Â mM, creating the possibility for applications requiring high substrate loading. Aliphatic ketones were also readily converted with excellent regioselectivity. Similar to CHMOacinet, acetophenones were not converted and the oxidation of rac-cis-bicyclo[3.2.0]hept-2-en-6-one occurs enantiodivergently, with the (1R,5S) isomer converted to the “normal” lactone and the (1S,5R) isomer to the “abnormal” lactone.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Enzyme and Microbial Technology - Volume 106, November 2017, Pages 11-17
Journal: Enzyme and Microbial Technology - Volume 106, November 2017, Pages 11-17
نویسندگان
Katlego Siphamandla Mthethwa, Karin Kassier, Jennifer Engel, Selin Kara, Martha Sophia Smit, Diederik Johannes Opperman,