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Improvement of activity and stability of chloroperoxidase by chemical modification

BACKGROUND: Enzymes show relative instability in solvents or at elevated temperature and lower activity in organic solvent than in water. These limit the industrial applications of enzymes. RESULTS: In order to improve the activity and stability of chloroperoxidase, chloroperoxidase was modified by...

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Autores principales: Liu, Jian-Zhong, Wang, Min
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2007
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1891289/
https://www.ncbi.nlm.nih.gov/pubmed/17511866
http://dx.doi.org/10.1186/1472-6750-7-23
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author Liu, Jian-Zhong
Wang, Min
author_facet Liu, Jian-Zhong
Wang, Min
author_sort Liu, Jian-Zhong
collection PubMed
description BACKGROUND: Enzymes show relative instability in solvents or at elevated temperature and lower activity in organic solvent than in water. These limit the industrial applications of enzymes. RESULTS: In order to improve the activity and stability of chloroperoxidase, chloroperoxidase was modified by citraconic anhydride, maleic anhydride or phthalic anhydride. The catalytic activities, thermostabilities and organic solvent tolerances of native and modified enzymes were compared. In aqueous buffer, modified chloroperoxidases showed similar K(m )values and greater catalytic efficiencies k(cat)/K(m )for both sulfoxidation and oxidation of phenol compared to native chloroperoxidase. Of these modified chloroperoxidases, citraconic anhydride-modified chloroperoxidase showed the greatest catalytic efficiency in aqueous buffer. These modifications of chloroperoxidase increased their catalytic efficiencies for sulfoxidation by 12%~26% and catalytic efficiencies for phenol oxidation by 7%~53% in aqueous buffer. However, in organic solvent (DMF), modified chloroperoxidases had lower K(m )values and higher catalytic efficiencies k(cat)/K(m )than native chloroperoxidase. These modifications also improved their thermostabilities by 1~2-fold and solvent tolerances of DMF. CD studies show that these modifications did not change the secondary structure of chloroperoxidase. Fluorescence spectra proved that these modifications changed the environment of tryptophan. CONCLUSION: Chemical modification of epsilon-amino groups of lysine residues of chloroperoxidase using citraconic anhydride, maleic anhydride or phthalic anhydride is a simple and powerful method to enhance catalytic properties of enzyme. The improvements of the activity and stability of chloroperoxidase are related to side chain reorientations of aromatics upon both modifications.
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spelling pubmed-18912892007-06-13 Improvement of activity and stability of chloroperoxidase by chemical modification Liu, Jian-Zhong Wang, Min BMC Biotechnol Research Article BACKGROUND: Enzymes show relative instability in solvents or at elevated temperature and lower activity in organic solvent than in water. These limit the industrial applications of enzymes. RESULTS: In order to improve the activity and stability of chloroperoxidase, chloroperoxidase was modified by citraconic anhydride, maleic anhydride or phthalic anhydride. The catalytic activities, thermostabilities and organic solvent tolerances of native and modified enzymes were compared. In aqueous buffer, modified chloroperoxidases showed similar K(m )values and greater catalytic efficiencies k(cat)/K(m )for both sulfoxidation and oxidation of phenol compared to native chloroperoxidase. Of these modified chloroperoxidases, citraconic anhydride-modified chloroperoxidase showed the greatest catalytic efficiency in aqueous buffer. These modifications of chloroperoxidase increased their catalytic efficiencies for sulfoxidation by 12%~26% and catalytic efficiencies for phenol oxidation by 7%~53% in aqueous buffer. However, in organic solvent (DMF), modified chloroperoxidases had lower K(m )values and higher catalytic efficiencies k(cat)/K(m )than native chloroperoxidase. These modifications also improved their thermostabilities by 1~2-fold and solvent tolerances of DMF. CD studies show that these modifications did not change the secondary structure of chloroperoxidase. Fluorescence spectra proved that these modifications changed the environment of tryptophan. CONCLUSION: Chemical modification of epsilon-amino groups of lysine residues of chloroperoxidase using citraconic anhydride, maleic anhydride or phthalic anhydride is a simple and powerful method to enhance catalytic properties of enzyme. The improvements of the activity and stability of chloroperoxidase are related to side chain reorientations of aromatics upon both modifications. BioMed Central 2007-05-18 /pmc/articles/PMC1891289/ /pubmed/17511866 http://dx.doi.org/10.1186/1472-6750-7-23 Text en Copyright © 2007 Liu and Wang; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( (http://creativecommons.org/licenses/by/2.0) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Liu, Jian-Zhong
Wang, Min
Improvement of activity and stability of chloroperoxidase by chemical modification
title Improvement of activity and stability of chloroperoxidase by chemical modification
title_full Improvement of activity and stability of chloroperoxidase by chemical modification
title_fullStr Improvement of activity and stability of chloroperoxidase by chemical modification
title_full_unstemmed Improvement of activity and stability of chloroperoxidase by chemical modification
title_short Improvement of activity and stability of chloroperoxidase by chemical modification
title_sort improvement of activity and stability of chloroperoxidase by chemical modification
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1891289/
https://www.ncbi.nlm.nih.gov/pubmed/17511866
http://dx.doi.org/10.1186/1472-6750-7-23
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