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Crystal structure and enzymatic properties of chalcone isomerase from the Antarctic vascular plant Deschampsia antarctica Desv.

Chalcone isomerase (CHI) is an important enzyme for flavonoid biosynthesis that catalyzes the intramolecular cyclization of chalcones into (S)-flavanones. CHIs have been classified into two types based on their substrate specificity. Type I CHIs use naringenin chalcone as a substrate and are found i...

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Autores principales: Park, Sun-Ha, Lee, Chang Woo, Cho, Sung Mi, Lee, Hyoungseok, Park, Hyun, Lee, Jungeun, Lee, Jun Hyuck
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5796730/
https://www.ncbi.nlm.nih.gov/pubmed/29394293
http://dx.doi.org/10.1371/journal.pone.0192415
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author Park, Sun-Ha
Lee, Chang Woo
Cho, Sung Mi
Lee, Hyoungseok
Park, Hyun
Lee, Jungeun
Lee, Jun Hyuck
author_facet Park, Sun-Ha
Lee, Chang Woo
Cho, Sung Mi
Lee, Hyoungseok
Park, Hyun
Lee, Jungeun
Lee, Jun Hyuck
author_sort Park, Sun-Ha
collection PubMed
description Chalcone isomerase (CHI) is an important enzyme for flavonoid biosynthesis that catalyzes the intramolecular cyclization of chalcones into (S)-flavanones. CHIs have been classified into two types based on their substrate specificity. Type I CHIs use naringenin chalcone as a substrate and are found in most of plants besides legumes, whereas type II CHIs in leguminous plants can also utilize isoliquiritigenin. In this study, we found that the CHI from the Antarctic plant Deschampsia antarctica (DaCHI1) is of type I based on sequence homology but can use type II CHI substrates. To clarify the enzymatic mechanism of DaCHI1 at the molecular level, the crystal structures of unliganded DaCHI1 and isoliquiritigenin-bound DaCHI1 were determined at 2.7 and 2.1 Å resolutions, respectively. The structures revealed that isoliquiritigenin binds to the active site of DaCHI1 and induces conformational changes. Additionally, the activity assay showed that while DaCHI1 exhibits substrate preference for naringenin chalcone, it can also utilize isoliquiritigenin although the catalytic activity was relatively low. Based on these results, we propose that DaCHI1 uses various substrates to produce antioxidant flavonoids as an adaptation to oxidative stresses associated with harsh environmental conditions.
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spelling pubmed-57967302018-02-16 Crystal structure and enzymatic properties of chalcone isomerase from the Antarctic vascular plant Deschampsia antarctica Desv. Park, Sun-Ha Lee, Chang Woo Cho, Sung Mi Lee, Hyoungseok Park, Hyun Lee, Jungeun Lee, Jun Hyuck PLoS One Research Article Chalcone isomerase (CHI) is an important enzyme for flavonoid biosynthesis that catalyzes the intramolecular cyclization of chalcones into (S)-flavanones. CHIs have been classified into two types based on their substrate specificity. Type I CHIs use naringenin chalcone as a substrate and are found in most of plants besides legumes, whereas type II CHIs in leguminous plants can also utilize isoliquiritigenin. In this study, we found that the CHI from the Antarctic plant Deschampsia antarctica (DaCHI1) is of type I based on sequence homology but can use type II CHI substrates. To clarify the enzymatic mechanism of DaCHI1 at the molecular level, the crystal structures of unliganded DaCHI1 and isoliquiritigenin-bound DaCHI1 were determined at 2.7 and 2.1 Å resolutions, respectively. The structures revealed that isoliquiritigenin binds to the active site of DaCHI1 and induces conformational changes. Additionally, the activity assay showed that while DaCHI1 exhibits substrate preference for naringenin chalcone, it can also utilize isoliquiritigenin although the catalytic activity was relatively low. Based on these results, we propose that DaCHI1 uses various substrates to produce antioxidant flavonoids as an adaptation to oxidative stresses associated with harsh environmental conditions. Public Library of Science 2018-02-02 /pmc/articles/PMC5796730/ /pubmed/29394293 http://dx.doi.org/10.1371/journal.pone.0192415 Text en © 2018 Park et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Park, Sun-Ha
Lee, Chang Woo
Cho, Sung Mi
Lee, Hyoungseok
Park, Hyun
Lee, Jungeun
Lee, Jun Hyuck
Crystal structure and enzymatic properties of chalcone isomerase from the Antarctic vascular plant Deschampsia antarctica Desv.
title Crystal structure and enzymatic properties of chalcone isomerase from the Antarctic vascular plant Deschampsia antarctica Desv.
title_full Crystal structure and enzymatic properties of chalcone isomerase from the Antarctic vascular plant Deschampsia antarctica Desv.
title_fullStr Crystal structure and enzymatic properties of chalcone isomerase from the Antarctic vascular plant Deschampsia antarctica Desv.
title_full_unstemmed Crystal structure and enzymatic properties of chalcone isomerase from the Antarctic vascular plant Deschampsia antarctica Desv.
title_short Crystal structure and enzymatic properties of chalcone isomerase from the Antarctic vascular plant Deschampsia antarctica Desv.
title_sort crystal structure and enzymatic properties of chalcone isomerase from the antarctic vascular plant deschampsia antarctica desv.
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5796730/
https://www.ncbi.nlm.nih.gov/pubmed/29394293
http://dx.doi.org/10.1371/journal.pone.0192415
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