Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH

Autores
Vila, Jorge Alberto
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Tautomeric identification by direct observation of 15N chemical shifts of the imidazole ring of histidine (His) has become a common practice in NMR spectroscopy. However, such applications require knowledge of the "canonical"? limiting values of the 15N chemical shift of the imidazole ring of His in which each form of His, namely, the protonated (H+) and the tautomeric Nε2 - H and N δ1 - H forms, respectively, is present to the extent of 100%. So far, the adopted canonical limiting values of the 15N chemical shift have been those available from model compounds. Whether these canonical values reflect those of the individual pure forms of His is investigated here by carrying out an analysis of the second-order shielding differences, ΔΔ = |Δε - Δδ |, with Δζ (ζ = ε or δ) being the density functional theory (DFT)-computed average shielding differences between the two nitrogens of the imidazole ring of His in each pure tautomeric form. In the high-pH limit, the results indicate that (i) the ΔΔ values from the DFT-computed shielding, but not from the commonly used canonical limiting values, are in closer agreement with those obtained with experimental chemical shift data from model compounds in solution and solid-state NMR; and (ii) the commonly used canonical limiting values of the 15N chemical shifts lead to an average tautomeric equilibrium constant that differs by a factor of ∼2.6 from the one computed by using DFT-based 15N limiting values, raising concern about the practice of using canonical limiting 15N values. This can be avoided by reporting tautomeric equilibrium constants computed by using only limiting 15N values for the N ε2 - H tautomer.
Fil: Vila, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; Argentina
Materia
SHIELDING
15N
VALIDATION
LIMITING VALUES
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/184758

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network_name_str CONICET Digital (CONICET)
spelling Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pHVila, Jorge AlbertoSHIELDING15NVALIDATIONLIMITING VALUEShttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Tautomeric identification by direct observation of 15N chemical shifts of the imidazole ring of histidine (His) has become a common practice in NMR spectroscopy. However, such applications require knowledge of the "canonical"? limiting values of the 15N chemical shift of the imidazole ring of His in which each form of His, namely, the protonated (H+) and the tautomeric Nε2 - H and N δ1 - H forms, respectively, is present to the extent of 100%. So far, the adopted canonical limiting values of the 15N chemical shift have been those available from model compounds. Whether these canonical values reflect those of the individual pure forms of His is investigated here by carrying out an analysis of the second-order shielding differences, ΔΔ = |Δε - Δδ |, with Δζ (ζ = ε or δ) being the density functional theory (DFT)-computed average shielding differences between the two nitrogens of the imidazole ring of His in each pure tautomeric form. In the high-pH limit, the results indicate that (i) the ΔΔ values from the DFT-computed shielding, but not from the commonly used canonical limiting values, are in closer agreement with those obtained with experimental chemical shift data from model compounds in solution and solid-state NMR; and (ii) the commonly used canonical limiting values of the 15N chemical shifts lead to an average tautomeric equilibrium constant that differs by a factor of ∼2.6 from the one computed by using DFT-based 15N limiting values, raising concern about the practice of using canonical limiting 15N values. This can be avoided by reporting tautomeric equilibrium constants computed by using only limiting 15N values for the N ε2 - H tautomer.Fil: Vila, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaAmerican Chemical Society2012-10info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/184758Vila, Jorge Alberto; Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH; American Chemical Society; Journal of Physical Chemistry B; 116; 23; 10-2012; 6665-66691520-6106CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1021/jp211196rinfo:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/10.1021/jp211196rinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:20:41Zoai:ri.conicet.gov.ar:11336/184758instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 10:20:41.52CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH
title Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH
spellingShingle Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH
Vila, Jorge Alberto
SHIELDING
15N
VALIDATION
LIMITING VALUES
title_short Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH
title_full Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH
title_fullStr Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH
title_full_unstemmed Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH
title_sort Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH
dc.creator.none.fl_str_mv Vila, Jorge Alberto
author Vila, Jorge Alberto
author_facet Vila, Jorge Alberto
author_role author
dc.subject.none.fl_str_mv SHIELDING
15N
VALIDATION
LIMITING VALUES
topic SHIELDING
15N
VALIDATION
LIMITING VALUES
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Tautomeric identification by direct observation of 15N chemical shifts of the imidazole ring of histidine (His) has become a common practice in NMR spectroscopy. However, such applications require knowledge of the "canonical"? limiting values of the 15N chemical shift of the imidazole ring of His in which each form of His, namely, the protonated (H+) and the tautomeric Nε2 - H and N δ1 - H forms, respectively, is present to the extent of 100%. So far, the adopted canonical limiting values of the 15N chemical shift have been those available from model compounds. Whether these canonical values reflect those of the individual pure forms of His is investigated here by carrying out an analysis of the second-order shielding differences, ΔΔ = |Δε - Δδ |, with Δζ (ζ = ε or δ) being the density functional theory (DFT)-computed average shielding differences between the two nitrogens of the imidazole ring of His in each pure tautomeric form. In the high-pH limit, the results indicate that (i) the ΔΔ values from the DFT-computed shielding, but not from the commonly used canonical limiting values, are in closer agreement with those obtained with experimental chemical shift data from model compounds in solution and solid-state NMR; and (ii) the commonly used canonical limiting values of the 15N chemical shifts lead to an average tautomeric equilibrium constant that differs by a factor of ∼2.6 from the one computed by using DFT-based 15N limiting values, raising concern about the practice of using canonical limiting 15N values. This can be avoided by reporting tautomeric equilibrium constants computed by using only limiting 15N values for the N ε2 - H tautomer.
Fil: Vila, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; Argentina
description Tautomeric identification by direct observation of 15N chemical shifts of the imidazole ring of histidine (His) has become a common practice in NMR spectroscopy. However, such applications require knowledge of the "canonical"? limiting values of the 15N chemical shift of the imidazole ring of His in which each form of His, namely, the protonated (H+) and the tautomeric Nε2 - H and N δ1 - H forms, respectively, is present to the extent of 100%. So far, the adopted canonical limiting values of the 15N chemical shift have been those available from model compounds. Whether these canonical values reflect those of the individual pure forms of His is investigated here by carrying out an analysis of the second-order shielding differences, ΔΔ = |Δε - Δδ |, with Δζ (ζ = ε or δ) being the density functional theory (DFT)-computed average shielding differences between the two nitrogens of the imidazole ring of His in each pure tautomeric form. In the high-pH limit, the results indicate that (i) the ΔΔ values from the DFT-computed shielding, but not from the commonly used canonical limiting values, are in closer agreement with those obtained with experimental chemical shift data from model compounds in solution and solid-state NMR; and (ii) the commonly used canonical limiting values of the 15N chemical shifts lead to an average tautomeric equilibrium constant that differs by a factor of ∼2.6 from the one computed by using DFT-based 15N limiting values, raising concern about the practice of using canonical limiting 15N values. This can be avoided by reporting tautomeric equilibrium constants computed by using only limiting 15N values for the N ε2 - H tautomer.
publishDate 2012
dc.date.none.fl_str_mv 2012-10
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/184758
Vila, Jorge Alberto; Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH; American Chemical Society; Journal of Physical Chemistry B; 116; 23; 10-2012; 6665-6669
1520-6106
CONICET Digital
CONICET
url http://hdl.handle.net/11336/184758
identifier_str_mv Vila, Jorge Alberto; Limiting values of the 15N chemical shift of the imidazole ring of histidine at high pH; American Chemical Society; Journal of Physical Chemistry B; 116; 23; 10-2012; 6665-6669
1520-6106
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1021/jp211196r
info:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/10.1021/jp211196r
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Chemical Society
publisher.none.fl_str_mv American Chemical Society
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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