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Theoretical Study of the Reactivity and Selectivity of Various Free Radicals with Cysteine Residues
[Image: see text] Radicals in biochemical environments can lead to protein damage. Theoretical studies can help us to understand the observed radical selectivity. In this work, the kinetics and thermodynamics of the hydrogen-transfer (HT) and single-electron transfer (SET) reactions between a cystei...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2018
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643617/ https://www.ncbi.nlm.nih.gov/pubmed/31458285 http://dx.doi.org/10.1021/acsomega.8b02964 |
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author | Romero-Silva, Antonio Mora-Diez, Nelaine Alvarez-Idaboy, J. Raul |
author_facet | Romero-Silva, Antonio Mora-Diez, Nelaine Alvarez-Idaboy, J. Raul |
author_sort | Romero-Silva, Antonio |
collection | PubMed |
description | [Image: see text] Radicals in biochemical environments can lead to protein damage. Theoretical studies can help us to understand the observed radical selectivity. In this work, the kinetics and thermodynamics of the hydrogen-transfer (HT) and single-electron transfer (SET) reactions between a cysteine derivative and 17 free radicals of biological significance have been theoretically investigated in aqueous and lipid media. With the exception of the reaction with (•)OCCl(3), all SET reactions in aqueous medium have rate constants in the diffusion-limited regime. The γ site of cysteine was found to be the most reactive for the HT reactions with all the radicals, with rate constants in the diffusion limit for (•)OH, (•)OCHCl(2), and (•)OCCl(3). The HT reactions from the α and γ positions have very similar ΔG° values and even though the β position is the least thermodynamically favored, when the HT from β is exergonic it is a more reactive site than α. The results obtained confirm that the Bell–Evans–Polanyi principle does not apply to the reactions between amino acid residues and free radicals and that reactivity comparisons demand proper kinetic calculations. |
format | Online Article Text |
id | pubmed-6643617 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-66436172019-08-27 Theoretical Study of the Reactivity and Selectivity of Various Free Radicals with Cysteine Residues Romero-Silva, Antonio Mora-Diez, Nelaine Alvarez-Idaboy, J. Raul ACS Omega [Image: see text] Radicals in biochemical environments can lead to protein damage. Theoretical studies can help us to understand the observed radical selectivity. In this work, the kinetics and thermodynamics of the hydrogen-transfer (HT) and single-electron transfer (SET) reactions between a cysteine derivative and 17 free radicals of biological significance have been theoretically investigated in aqueous and lipid media. With the exception of the reaction with (•)OCCl(3), all SET reactions in aqueous medium have rate constants in the diffusion-limited regime. The γ site of cysteine was found to be the most reactive for the HT reactions with all the radicals, with rate constants in the diffusion limit for (•)OH, (•)OCHCl(2), and (•)OCCl(3). The HT reactions from the α and γ positions have very similar ΔG° values and even though the β position is the least thermodynamically favored, when the HT from β is exergonic it is a more reactive site than α. The results obtained confirm that the Bell–Evans–Polanyi principle does not apply to the reactions between amino acid residues and free radicals and that reactivity comparisons demand proper kinetic calculations. American Chemical Society 2018-12-04 /pmc/articles/PMC6643617/ /pubmed/31458285 http://dx.doi.org/10.1021/acsomega.8b02964 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 | Romero-Silva, Antonio Mora-Diez, Nelaine Alvarez-Idaboy, J. Raul Theoretical Study of the Reactivity and Selectivity of Various Free Radicals with Cysteine Residues |
title | Theoretical Study of the Reactivity and Selectivity
of Various Free Radicals with Cysteine Residues |
title_full | Theoretical Study of the Reactivity and Selectivity
of Various Free Radicals with Cysteine Residues |
title_fullStr | Theoretical Study of the Reactivity and Selectivity
of Various Free Radicals with Cysteine Residues |
title_full_unstemmed | Theoretical Study of the Reactivity and Selectivity
of Various Free Radicals with Cysteine Residues |
title_short | Theoretical Study of the Reactivity and Selectivity
of Various Free Radicals with Cysteine Residues |
title_sort | theoretical study of the reactivity and selectivity
of various free radicals with cysteine residues |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643617/ https://www.ncbi.nlm.nih.gov/pubmed/31458285 http://dx.doi.org/10.1021/acsomega.8b02964 |
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