Solvation and Proton-Coupled Electron Transfer Reduction Potential of 2NO• to 1HNO in Aqueous Solution: A Theoretical Investigation

In this work, quantum mechanical calculations and Monte Carlo statistical mechanical simulations were carried out to investigate the solvation properties of HNO in aqueous solution and to evaluate the proton-coupled one electron reduction potential of 2NO to 1HNO, which is essential missing informat...

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Publicado: 2017
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pH
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v121_n27_p6618_Venancio
http://hdl.handle.net/20.500.12110/paper_15206106_v121_n27_p6618_Venancio
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spelling paper:paper_15206106_v121_n27_p6618_Venancio2023-06-08T16:19:11Z Solvation and Proton-Coupled Electron Transfer Reduction Potential of 2NO• to 1HNO in Aqueous Solution: A Theoretical Investigation Amino acids Bioinformatics Electron transitions Free energy Free radical reactions Hydrogen bonds Monte Carlo methods pH Physiology Quantum theory Solutions Solvation Hydration free energies Linear-response theory One-electron reduction potentials Physiological condition Proton coupled electron transfers Quantum-mechanical calculation Solvation free energies Theoretical investigations Reduction In this work, quantum mechanical calculations and Monte Carlo statistical mechanical simulations were carried out to investigate the solvation properties of HNO in aqueous solution and to evaluate the proton-coupled one electron reduction potential of 2NO to 1HNO, which is essential missing information to understand the fate of 2NO in the biological medium. Our results showed that the 1HNO molecule acts mainly as a hydrogen bond donor in aqueous solution with an average energy of -5.5 ± 1.3 kcal/mol. The solvation free energy of 1HNO in aqueous solution, computed using three approaches based on the linear response theory, revealed that the current prediction of the hydration free energy of HNO is, at least, 2 times underestimated. We proposed two pathways for the production of HNO through reduction of NO. The first pathway is the direct reduction of NO through proton-coupled electron transfer to produce HNO, and the second path is the reduction of the radical anion HONO•-, which is involved in equilibrium with NO in aqueous solution. We have shown that both pathways are viable processes under physiological conditions, having reduction potentials of E°′ = -0.161 V and E°′ ≈ 1 V for the first and second pathways, respectively. The results shows that both processes can be promoted by well-known biological reductants such as NADH, ascorbate, vitamin E (tocopherol), cysteine, and glutathione, for which the reduction potential at physiological pH is around -0.3 to -0.5 V. The computed reduction potential of NO through the radical anion HONO•- can also explain the recent experimental findings on the formation of HNO through the reduction of NO, promoted by H2S, vitamin C, and aromatic alcohols. Therefore, these results contribute to shed some light into the question of whether and how HNO is produced in vivo and also for the understanding of the biochemical and physiological effects of NO. © 2017 American Chemical Society. 2017 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v121_n27_p6618_Venancio http://hdl.handle.net/20.500.12110/paper_15206106_v121_n27_p6618_Venancio
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Amino acids
Bioinformatics
Electron transitions
Free energy
Free radical reactions
Hydrogen bonds
Monte Carlo methods
pH
Physiology
Quantum theory
Solutions
Solvation
Hydration free energies
Linear-response theory
One-electron reduction potentials
Physiological condition
Proton coupled electron transfers
Quantum-mechanical calculation
Solvation free energies
Theoretical investigations
Reduction
spellingShingle Amino acids
Bioinformatics
Electron transitions
Free energy
Free radical reactions
Hydrogen bonds
Monte Carlo methods
pH
Physiology
Quantum theory
Solutions
Solvation
Hydration free energies
Linear-response theory
One-electron reduction potentials
Physiological condition
Proton coupled electron transfers
Quantum-mechanical calculation
Solvation free energies
Theoretical investigations
Reduction
Solvation and Proton-Coupled Electron Transfer Reduction Potential of 2NO• to 1HNO in Aqueous Solution: A Theoretical Investigation
topic_facet Amino acids
Bioinformatics
Electron transitions
Free energy
Free radical reactions
Hydrogen bonds
Monte Carlo methods
pH
Physiology
Quantum theory
Solutions
Solvation
Hydration free energies
Linear-response theory
One-electron reduction potentials
Physiological condition
Proton coupled electron transfers
Quantum-mechanical calculation
Solvation free energies
Theoretical investigations
Reduction
description In this work, quantum mechanical calculations and Monte Carlo statistical mechanical simulations were carried out to investigate the solvation properties of HNO in aqueous solution and to evaluate the proton-coupled one electron reduction potential of 2NO to 1HNO, which is essential missing information to understand the fate of 2NO in the biological medium. Our results showed that the 1HNO molecule acts mainly as a hydrogen bond donor in aqueous solution with an average energy of -5.5 ± 1.3 kcal/mol. The solvation free energy of 1HNO in aqueous solution, computed using three approaches based on the linear response theory, revealed that the current prediction of the hydration free energy of HNO is, at least, 2 times underestimated. We proposed two pathways for the production of HNO through reduction of NO. The first pathway is the direct reduction of NO through proton-coupled electron transfer to produce HNO, and the second path is the reduction of the radical anion HONO•-, which is involved in equilibrium with NO in aqueous solution. We have shown that both pathways are viable processes under physiological conditions, having reduction potentials of E°′ = -0.161 V and E°′ ≈ 1 V for the first and second pathways, respectively. The results shows that both processes can be promoted by well-known biological reductants such as NADH, ascorbate, vitamin E (tocopherol), cysteine, and glutathione, for which the reduction potential at physiological pH is around -0.3 to -0.5 V. The computed reduction potential of NO through the radical anion HONO•- can also explain the recent experimental findings on the formation of HNO through the reduction of NO, promoted by H2S, vitamin C, and aromatic alcohols. Therefore, these results contribute to shed some light into the question of whether and how HNO is produced in vivo and also for the understanding of the biochemical and physiological effects of NO. © 2017 American Chemical Society.
title Solvation and Proton-Coupled Electron Transfer Reduction Potential of 2NO• to 1HNO in Aqueous Solution: A Theoretical Investigation
title_short Solvation and Proton-Coupled Electron Transfer Reduction Potential of 2NO• to 1HNO in Aqueous Solution: A Theoretical Investigation
title_full Solvation and Proton-Coupled Electron Transfer Reduction Potential of 2NO• to 1HNO in Aqueous Solution: A Theoretical Investigation
title_fullStr Solvation and Proton-Coupled Electron Transfer Reduction Potential of 2NO• to 1HNO in Aqueous Solution: A Theoretical Investigation
title_full_unstemmed Solvation and Proton-Coupled Electron Transfer Reduction Potential of 2NO• to 1HNO in Aqueous Solution: A Theoretical Investigation
title_sort solvation and proton-coupled electron transfer reduction potential of 2no• to 1hno in aqueous solution: a theoretical investigation
publishDate 2017
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v121_n27_p6618_Venancio
http://hdl.handle.net/20.500.12110/paper_15206106_v121_n27_p6618_Venancio
_version_ 1768543292386967552