Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism

Autores
Montaña, Maria Paulina; Blasich, Néstor Fabian; Haggi, Ernesto Sergio; Garcia, Norman Andino
Año de publicación
2009
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Considering the significance of visible light-promoted reactions in complex biological media, the photo-oxidation of the amino acids (AAs) tyrosine (tyr) and tryptophan (trp) was studied in the presence of the naturally occurring oxidative scavenger uracil (ur). The involved photoprocesses, studied at pH 7 and 9, are driven through the reactive oxygen species (ROS) singlet molecular oxygen (O2(1Äg)), superoxide radical anion (O2•−) and hydrogen peroxide (H2O2). The effect on the effectiveness of the overall photo-oxidation process due to the presence of an added electron-donating substrate such as ur is not straightforwardly predictable. The addition of the pyrimidine compound, a much lesser photo-oxidizable substrate than the AAs themselves, produced different results: (1) antioxidative for tyr at pH 9, decreasing the overall rate of oxygen uptake; (2) synergistic for tyr at pH 7, increasing the oxidation rate more than the corresponding addition value of the respective individual rates and (3) no effect for trp at both pH values. The final result depends on the respective abilities of the substrates as quenchers of both the long-lived riboflavin triplet excited state and the generated ROS and the pH of the medium. An interpretation for the different cases is attempted through a kinetic and mechanistic analysis.
Fil: Montaña, Maria Paulina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina
Fil: Blasich, Néstor Fabian. Universidad Nacional de la Patagonia Austral; Argentina
Fil: Haggi, Ernesto Sergio. Universidad Nacional de la Patagonia Austral; Argentina
Fil: Garcia, Norman Andino. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina
Materia
PHOTOOXIDATION
TRYPTOPHAN
TYROSINE
URACIL
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:11336/94119
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/94119
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repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanismMontaña, Maria PaulinaBlasich, Néstor FabianHaggi, Ernesto SergioGarcia, Norman AndinoPHOTOOXIDATIONTRYPTOPHANTYROSINEURACILhttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1Considering the significance of visible light-promoted reactions in complex biological media, the photo-oxidation of the amino acids (AAs) tyrosine (tyr) and tryptophan (trp) was studied in the presence of the naturally occurring oxidative scavenger uracil (ur). The involved photoprocesses, studied at pH 7 and 9, are driven through the reactive oxygen species (ROS) singlet molecular oxygen (O2(1Äg)), superoxide radical anion (O2•−) and hydrogen peroxide (H2O2). The effect on the effectiveness of the overall photo-oxidation process due to the presence of an added electron-donating substrate such as ur is not straightforwardly predictable. The addition of the pyrimidine compound, a much lesser photo-oxidizable substrate than the AAs themselves, produced different results: (1) antioxidative for tyr at pH 9, decreasing the overall rate of oxygen uptake; (2) synergistic for tyr at pH 7, increasing the oxidation rate more than the corresponding addition value of the respective individual rates and (3) no effect for trp at both pH values. The final result depends on the respective abilities of the substrates as quenchers of both the long-lived riboflavin triplet excited state and the generated ROS and the pH of the medium. An interpretation for the different cases is attempted through a kinetic and mechanistic analysis.Fil: Montaña, Maria Paulina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Blasich, Néstor Fabian. Universidad Nacional de la Patagonia Austral; ArgentinaFil: Haggi, Ernesto Sergio. Universidad Nacional de la Patagonia Austral; ArgentinaFil: Garcia, Norman Andino. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaWiley Blackwell Publishing, Inc2009-09info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/94119Montaña, Maria Paulina; Blasich, Néstor Fabian; Haggi, Ernesto Sergio; Garcia, Norman Andino; Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism; Wiley Blackwell Publishing, Inc; Photochemistry and Photobiology; 85; 5; 9-2009; 1097-11020031-86551751-1097CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://onlinelibrary.wiley.com/doi/full/10.1111/j.1751-1097.2009.00567.xinfo:eu-repo/semantics/altIdentifier/doi/10.1111/j.1751-1097.2009.00567.xinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-22T11:39:10Zoai:ri.conicet.gov.ar:11336/94119instacron: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:34982025-10-22 11:39:10.44CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism
title Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism
spellingShingle Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism
Montaña, Maria Paulina
PHOTOOXIDATION
TRYPTOPHAN
TYROSINE
URACIL
title_short Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism
title_full Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism
title_fullStr Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism
title_full_unstemmed Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism
title_sort Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism
dc.creator.none.fl_str_mv Montaña, Maria Paulina
Blasich, Néstor Fabian
Haggi, Ernesto Sergio
Garcia, Norman Andino
author Montaña, Maria Paulina
author_facet Montaña, Maria Paulina
Blasich, Néstor Fabian
Haggi, Ernesto Sergio
Garcia, Norman Andino
author_role author
author2 Blasich, Néstor Fabian
Haggi, Ernesto Sergio
Garcia, Norman Andino
author2_role author
author
author
dc.subject.none.fl_str_mv PHOTOOXIDATION
TRYPTOPHAN
TYROSINE
URACIL
topic PHOTOOXIDATION
TRYPTOPHAN
TYROSINE
URACIL
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Considering the significance of visible light-promoted reactions in complex biological media, the photo-oxidation of the amino acids (AAs) tyrosine (tyr) and tryptophan (trp) was studied in the presence of the naturally occurring oxidative scavenger uracil (ur). The involved photoprocesses, studied at pH 7 and 9, are driven through the reactive oxygen species (ROS) singlet molecular oxygen (O2(1Äg)), superoxide radical anion (O2•−) and hydrogen peroxide (H2O2). The effect on the effectiveness of the overall photo-oxidation process due to the presence of an added electron-donating substrate such as ur is not straightforwardly predictable. The addition of the pyrimidine compound, a much lesser photo-oxidizable substrate than the AAs themselves, produced different results: (1) antioxidative for tyr at pH 9, decreasing the overall rate of oxygen uptake; (2) synergistic for tyr at pH 7, increasing the oxidation rate more than the corresponding addition value of the respective individual rates and (3) no effect for trp at both pH values. The final result depends on the respective abilities of the substrates as quenchers of both the long-lived riboflavin triplet excited state and the generated ROS and the pH of the medium. An interpretation for the different cases is attempted through a kinetic and mechanistic analysis.
Fil: Montaña, Maria Paulina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina
Fil: Blasich, Néstor Fabian. Universidad Nacional de la Patagonia Austral; Argentina
Fil: Haggi, Ernesto Sergio. Universidad Nacional de la Patagonia Austral; Argentina
Fil: Garcia, Norman Andino. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina
description Considering the significance of visible light-promoted reactions in complex biological media, the photo-oxidation of the amino acids (AAs) tyrosine (tyr) and tryptophan (trp) was studied in the presence of the naturally occurring oxidative scavenger uracil (ur). The involved photoprocesses, studied at pH 7 and 9, are driven through the reactive oxygen species (ROS) singlet molecular oxygen (O2(1Äg)), superoxide radical anion (O2•−) and hydrogen peroxide (H2O2). The effect on the effectiveness of the overall photo-oxidation process due to the presence of an added electron-donating substrate such as ur is not straightforwardly predictable. The addition of the pyrimidine compound, a much lesser photo-oxidizable substrate than the AAs themselves, produced different results: (1) antioxidative for tyr at pH 9, decreasing the overall rate of oxygen uptake; (2) synergistic for tyr at pH 7, increasing the oxidation rate more than the corresponding addition value of the respective individual rates and (3) no effect for trp at both pH values. The final result depends on the respective abilities of the substrates as quenchers of both the long-lived riboflavin triplet excited state and the generated ROS and the pH of the medium. An interpretation for the different cases is attempted through a kinetic and mechanistic analysis.
publishDate 2009
dc.date.none.fl_str_mv 2009-09
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/11336/94119
Montaña, Maria Paulina; Blasich, Néstor Fabian; Haggi, Ernesto Sergio; Garcia, Norman Andino; Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism; Wiley Blackwell Publishing, Inc; Photochemistry and Photobiology; 85; 5; 9-2009; 1097-1102
0031-8655
1751-1097
CONICET Digital
CONICET
url http://hdl.handle.net/11336/94119
identifier_str_mv Montaña, Maria Paulina; Blasich, Néstor Fabian; Haggi, Ernesto Sergio; Garcia, Norman Andino; Oxygen uptake in the vitamin B2-sensitized photo-oxidation of tyrosine and tryptophan in the presence of uracil: Kinetics and mechanism; Wiley Blackwell Publishing, Inc; Photochemistry and Photobiology; 85; 5; 9-2009; 1097-1102
0031-8655
1751-1097
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://onlinelibrary.wiley.com/doi/full/10.1111/j.1751-1097.2009.00567.x
info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1751-1097.2009.00567.x
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
application/pdf
dc.publisher.none.fl_str_mv Wiley Blackwell Publishing, Inc
publisher.none.fl_str_mv Wiley Blackwell Publishing, Inc
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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score 12.982451

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