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Structural Insight into Substrate Selectivity of Erwinia chrysanthemil-Asparaginase
[Image: see text] l-Asparaginases of bacterial origin are a mainstay of acute lymphoblastic leukemia treatment. The mechanism of action of these enzyme drugs is associated with their capacity to deplete the amino acid l-asparagine from the blood. However, clinical use of bacterial l-asparaginases is...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American
Chemical Society
2016
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4776285/ https://www.ncbi.nlm.nih.gov/pubmed/26855287 http://dx.doi.org/10.1021/acs.biochem.5b01351 |
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author | Nguyen, Hien Anh Su, Ying Lavie, Arnon |
author_facet | Nguyen, Hien Anh Su, Ying Lavie, Arnon |
author_sort | Nguyen, Hien Anh |
collection | PubMed |
description | [Image: see text] l-Asparaginases of bacterial origin are a mainstay of acute lymphoblastic leukemia treatment. The mechanism of action of these enzyme drugs is associated with their capacity to deplete the amino acid l-asparagine from the blood. However, clinical use of bacterial l-asparaginases is complicated by their dual l-asparaginase and l-glutaminase activities. The latter, even though representing only ∼10% of the overall activity, is partially responsible for the observed toxic side effects. Hence, l-asparaginases devoid of l-glutaminase activity hold potential as safer drugs. Understanding the key determinants of l-asparaginase substrate specificity is a prerequisite step toward the development of enzyme variants with reduced toxicity. Here we present crystal structures of the Erwinia chrysanthemil-asparaginase in complex with l-aspartic acid and with l-glutamic acid. These structures reveal two enzyme conformations—open and closed—corresponding to the inactive and active states, respectively. The binding of ligands induces the positioning of the catalytic Thr15 into its active conformation, which in turn allows for the ordering and closure of the flexible N-terminal loop. Notably, l-aspartic acid is more efficient than l-glutamic acid in inducing the active positioning of Thr15. Structural elements explaining the preference of the enzyme for l-asparagine over l-glutamine are discussed with guidance to the future development of more specific l-asparaginases. |
format | Online Article Text |
id | pubmed-4776285 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | American
Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-47762852016-03-07 Structural Insight into Substrate Selectivity of Erwinia chrysanthemil-Asparaginase Nguyen, Hien Anh Su, Ying Lavie, Arnon Biochemistry [Image: see text] l-Asparaginases of bacterial origin are a mainstay of acute lymphoblastic leukemia treatment. The mechanism of action of these enzyme drugs is associated with their capacity to deplete the amino acid l-asparagine from the blood. However, clinical use of bacterial l-asparaginases is complicated by their dual l-asparaginase and l-glutaminase activities. The latter, even though representing only ∼10% of the overall activity, is partially responsible for the observed toxic side effects. Hence, l-asparaginases devoid of l-glutaminase activity hold potential as safer drugs. Understanding the key determinants of l-asparaginase substrate specificity is a prerequisite step toward the development of enzyme variants with reduced toxicity. Here we present crystal structures of the Erwinia chrysanthemil-asparaginase in complex with l-aspartic acid and with l-glutamic acid. These structures reveal two enzyme conformations—open and closed—corresponding to the inactive and active states, respectively. The binding of ligands induces the positioning of the catalytic Thr15 into its active conformation, which in turn allows for the ordering and closure of the flexible N-terminal loop. Notably, l-aspartic acid is more efficient than l-glutamic acid in inducing the active positioning of Thr15. Structural elements explaining the preference of the enzyme for l-asparagine over l-glutamine are discussed with guidance to the future development of more specific l-asparaginases. American Chemical Society 2016-02-08 2016-03-01 /pmc/articles/PMC4776285/ /pubmed/26855287 http://dx.doi.org/10.1021/acs.biochem.5b01351 Text en Copyright © 2016 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 | Nguyen, Hien Anh Su, Ying Lavie, Arnon Structural Insight into Substrate Selectivity of Erwinia chrysanthemil-Asparaginase |
title | Structural Insight into Substrate Selectivity of Erwinia chrysanthemil-Asparaginase |
title_full | Structural Insight into Substrate Selectivity of Erwinia chrysanthemil-Asparaginase |
title_fullStr | Structural Insight into Substrate Selectivity of Erwinia chrysanthemil-Asparaginase |
title_full_unstemmed | Structural Insight into Substrate Selectivity of Erwinia chrysanthemil-Asparaginase |
title_short | Structural Insight into Substrate Selectivity of Erwinia chrysanthemil-Asparaginase |
title_sort | structural insight into substrate selectivity of erwinia chrysanthemil-asparaginase |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4776285/ https://www.ncbi.nlm.nih.gov/pubmed/26855287 http://dx.doi.org/10.1021/acs.biochem.5b01351 |
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