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Diverse Engineered Heme Proteins Enable Stereodivergent Cyclopropanation of Unactivated Alkenes

[Image: see text] Developing catalysts that produce each stereoisomer of a desired product selectively is a longstanding synthetic challenge. Biochemists have addressed this challenge by screening nature’s diversity to discover enzymes that catalyze the formation of complementary stereoisomers. We s...

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Autores principales: Knight, Anders M., Kan, S. B. Jennifer, Lewis, Russell D., Brandenberg, Oliver F., Chen, Kai, Arnold, Frances H.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2018
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5879470/
https://www.ncbi.nlm.nih.gov/pubmed/29632883
http://dx.doi.org/10.1021/acscentsci.7b00548
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author Knight, Anders M.
Kan, S. B. Jennifer
Lewis, Russell D.
Brandenberg, Oliver F.
Chen, Kai
Arnold, Frances H.
author_facet Knight, Anders M.
Kan, S. B. Jennifer
Lewis, Russell D.
Brandenberg, Oliver F.
Chen, Kai
Arnold, Frances H.
author_sort Knight, Anders M.
collection PubMed
description [Image: see text] Developing catalysts that produce each stereoisomer of a desired product selectively is a longstanding synthetic challenge. Biochemists have addressed this challenge by screening nature’s diversity to discover enzymes that catalyze the formation of complementary stereoisomers. We show here that the same approach can be applied to a new-to-nature enzymatic reaction, alkene cyclopropanation via carbene transfer. By screening diverse native and engineered heme proteins, we identified globins and serine-ligated “P411” variants of cytochromes P450 with promiscuous activity for cyclopropanation of unactivated alkene substrates. We then enhanced their activities and stereoselectivities by directed evolution: just 1–3 rounds of site-saturation mutagenesis and screening generated enzymes that transform unactivated alkenes and electron-deficient alkenes into each of the four stereoisomeric cyclopropanes with up to 5,400 total turnovers and 98% enantiomeric excess. These fully genetically encoded biocatalysts function in whole Escherichia coli cells in mild, aqueous conditions and provide the first example of enantioselective, intermolecular iron-catalyzed cyclopropanation of unactivated alkenes.
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spelling pubmed-58794702018-04-09 Diverse Engineered Heme Proteins Enable Stereodivergent Cyclopropanation of Unactivated Alkenes Knight, Anders M. Kan, S. B. Jennifer Lewis, Russell D. Brandenberg, Oliver F. Chen, Kai Arnold, Frances H. ACS Cent Sci [Image: see text] Developing catalysts that produce each stereoisomer of a desired product selectively is a longstanding synthetic challenge. Biochemists have addressed this challenge by screening nature’s diversity to discover enzymes that catalyze the formation of complementary stereoisomers. We show here that the same approach can be applied to a new-to-nature enzymatic reaction, alkene cyclopropanation via carbene transfer. By screening diverse native and engineered heme proteins, we identified globins and serine-ligated “P411” variants of cytochromes P450 with promiscuous activity for cyclopropanation of unactivated alkene substrates. We then enhanced their activities and stereoselectivities by directed evolution: just 1–3 rounds of site-saturation mutagenesis and screening generated enzymes that transform unactivated alkenes and electron-deficient alkenes into each of the four stereoisomeric cyclopropanes with up to 5,400 total turnovers and 98% enantiomeric excess. These fully genetically encoded biocatalysts function in whole Escherichia coli cells in mild, aqueous conditions and provide the first example of enantioselective, intermolecular iron-catalyzed cyclopropanation of unactivated alkenes. American Chemical Society 2018-02-21 2018-03-28 /pmc/articles/PMC5879470/ /pubmed/29632883 http://dx.doi.org/10.1021/acscentsci.7b00548 Text en Copyright © 2018 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
spellingShingle Knight, Anders M.
Kan, S. B. Jennifer
Lewis, Russell D.
Brandenberg, Oliver F.
Chen, Kai
Arnold, Frances H.
Diverse Engineered Heme Proteins Enable Stereodivergent Cyclopropanation of Unactivated Alkenes
title Diverse Engineered Heme Proteins Enable Stereodivergent Cyclopropanation of Unactivated Alkenes
title_full Diverse Engineered Heme Proteins Enable Stereodivergent Cyclopropanation of Unactivated Alkenes
title_fullStr Diverse Engineered Heme Proteins Enable Stereodivergent Cyclopropanation of Unactivated Alkenes
title_full_unstemmed Diverse Engineered Heme Proteins Enable Stereodivergent Cyclopropanation of Unactivated Alkenes
title_short Diverse Engineered Heme Proteins Enable Stereodivergent Cyclopropanation of Unactivated Alkenes
title_sort diverse engineered heme proteins enable stereodivergent cyclopropanation of unactivated alkenes
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5879470/
https://www.ncbi.nlm.nih.gov/pubmed/29632883
http://dx.doi.org/10.1021/acscentsci.7b00548
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