Myoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosis
Autor(a) principal: | |
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Data de Publicação: | 2011 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNIFESP |
Texto Completo: | http://repositorio.unifesp.br/handle/11600/33896 http://dx.doi.org/10.1016/j.freeradbiomed.2011.05.002 |
Resumo: | Acetoacetate (AA) and 2-methylacetoacetate (MAA) are accumulated in metabolic disorders such as diabetes and isoleucinemia. Here we examine the mechanism of AA and MAA aerobic oxidation initiated by myoglobin (Mb)/H2O2. We propose a chemiluminescent route involving a dioxetanone intermediate whose thermolysis yields triplet alpha-dicarbonyl species (methylglyoxal and diacetyl). the observed ultraweak chemiluminescence increased linearly on raising the concentration of either Mb (10-500 mu M) or AA (10-100 mM). Oxygen uptake studies revealed that MAA is almost a 100-fold more reactive than AA. EPR spin-trapping studies with MNP/MAA revealed the intermediacy of an alpha-carbon-centered radical and acetyl radical. the latter radical, probably derived from triplet diacetyl, is totally suppressed by sorbate, a well-known quencher of triplet carbonyls. Furthermore, an EPR signal assignable to MNP-AA(center dot) adduct was observed and confirmed by isotope effects. Oxygen consumption and a-dicarbonyl yield were shown to be dependent on AA or MAA concentrations (1-50 mM) and on H2O2 or tert-butOOH added to the Mb-containing reaction mixtures. That ferrylMb is involved in a peroxidase cycle acting on the substrates is suggested by the reaction pH profiles and immunospin-trapping experiments. the generation of radicals and triplet dicarbonyl products by Mb/H2O2/beta-ketoacids may contribute to the adverse health effects of ketogenic unbalance. (C) 2011 Elsevier Inc. All rights reserved. |
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Ganini, DouglasChristoff, MarceloEhrenshaft, MarilynKadiiska, Maria B.Mason, Ronald P.Bechara, Etelvino José Henriques [UNIFESP]Universidade Federal de São Paulo (UNIFESP)Universidade de São Paulo (USP)Natl Inst Environm Hlth Sci2016-01-24T14:17:01Z2016-01-24T14:17:01Z2011-08-01Free Radical Biology and Medicine. New York: Elsevier B.V., v. 51, n. 3, p. 733-743, 2011.0891-5849http://repositorio.unifesp.br/handle/11600/33896http://dx.doi.org/10.1016/j.freeradbiomed.2011.05.002WOS000292856900017.pdf10.1016/j.freeradbiomed.2011.05.002WOS:000292856900017Acetoacetate (AA) and 2-methylacetoacetate (MAA) are accumulated in metabolic disorders such as diabetes and isoleucinemia. Here we examine the mechanism of AA and MAA aerobic oxidation initiated by myoglobin (Mb)/H2O2. We propose a chemiluminescent route involving a dioxetanone intermediate whose thermolysis yields triplet alpha-dicarbonyl species (methylglyoxal and diacetyl). the observed ultraweak chemiluminescence increased linearly on raising the concentration of either Mb (10-500 mu M) or AA (10-100 mM). Oxygen uptake studies revealed that MAA is almost a 100-fold more reactive than AA. EPR spin-trapping studies with MNP/MAA revealed the intermediacy of an alpha-carbon-centered radical and acetyl radical. the latter radical, probably derived from triplet diacetyl, is totally suppressed by sorbate, a well-known quencher of triplet carbonyls. Furthermore, an EPR signal assignable to MNP-AA(center dot) adduct was observed and confirmed by isotope effects. Oxygen consumption and a-dicarbonyl yield were shown to be dependent on AA or MAA concentrations (1-50 mM) and on H2O2 or tert-butOOH added to the Mb-containing reaction mixtures. That ferrylMb is involved in a peroxidase cycle acting on the substrates is suggested by the reaction pH profiles and immunospin-trapping experiments. the generation of radicals and triplet dicarbonyl products by Mb/H2O2/beta-ketoacids may contribute to the adverse health effects of ketogenic unbalance. (C) 2011 Elsevier Inc. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Instituto Nacional de Ciencia e Tecnologia (INCT) RedoxomaNational Institute of Environmental Health Sciences (NIEHS)Universidade Federal de São Paulo, Dept Ciencias Exatas & Terra, Inst Ciencias Ambientais Quim & Farmaceut, BR-00972270 Diadema, SP, BrazilUniv São Paulo, Inst Quim, Dept Bioquim, BR-01498 São Paulo, BrazilNatl Inst Environm Hlth Sci, Free Rad Metab Grp, Lab Toxicol & Pharmacol, NIH, Res Triangle Pk, NC 27709 USAUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, Inst Ciencias Ambientais Quim & Farmaceut, BR-00972270 Diadema, SP, BrazilWeb of Science733-743engElsevier B.V.Free Radical Biology and Medicinehttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policyinfo:eu-repo/semantics/openAccessMyoglobinAcetoacetate2-MethylacetoacetateFree radicalsTriplet carbonylsMethylglyoxalDiacetylKetosisMyoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosisinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlereponame:Repositório Institucional da UNIFESPinstname:Universidade Federal de São Paulo (UNIFESP)instacron:UNIFESPORIGINALWOS000292856900017.pdfapplication/pdf1557361${dspace.ui.url}/bitstream/11600/33896/1/WOS000292856900017.pdfdf284a079162aa3681e93d2bc9223616MD51open accessTEXTWOS000292856900017.pdf.txtWOS000292856900017.pdf.txtExtracted texttext/plain52612${dspace.ui.url}/bitstream/11600/33896/9/WOS000292856900017.pdf.txt225731409176ce7598bea1e50b13a24eMD59open accessTHUMBNAILWOS000292856900017.pdf.jpgWOS000292856900017.pdf.jpgIM Thumbnailimage/jpeg7817${dspace.ui.url}/bitstream/11600/33896/11/WOS000292856900017.pdf.jpg44bdba22fb737b7504db1c69f85d93a4MD511open access11600/338962023-06-05 19:21:17.124open accessoai:repositorio.unifesp.br:11600/33896Repositório InstitucionalPUBhttp://www.repositorio.unifesp.br/oai/requestopendoar:34652023-06-05T22:21:17Repositório Institucional da UNIFESP - Universidade Federal de São Paulo (UNIFESP)false |
dc.title.en.fl_str_mv |
Myoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosis |
title |
Myoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosis |
spellingShingle |
Myoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosis Ganini, Douglas Myoglobin Acetoacetate 2-Methylacetoacetate Free radicals Triplet carbonyls Methylglyoxal Diacetyl Ketosis |
title_short |
Myoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosis |
title_full |
Myoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosis |
title_fullStr |
Myoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosis |
title_full_unstemmed |
Myoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosis |
title_sort |
Myoglobin-H2O2 catalyzes the oxidation of beta-ketoacids to alpha-dicarbonyls: Mechanism and implications in ketosis |
author |
Ganini, Douglas |
author_facet |
Ganini, Douglas Christoff, Marcelo Ehrenshaft, Marilyn Kadiiska, Maria B. Mason, Ronald P. Bechara, Etelvino José Henriques [UNIFESP] |
author_role |
author |
author2 |
Christoff, Marcelo Ehrenshaft, Marilyn Kadiiska, Maria B. Mason, Ronald P. Bechara, Etelvino José Henriques [UNIFESP] |
author2_role |
author author author author author |
dc.contributor.institution.none.fl_str_mv |
Universidade Federal de São Paulo (UNIFESP) Universidade de São Paulo (USP) Natl Inst Environm Hlth Sci |
dc.contributor.author.fl_str_mv |
Ganini, Douglas Christoff, Marcelo Ehrenshaft, Marilyn Kadiiska, Maria B. Mason, Ronald P. Bechara, Etelvino José Henriques [UNIFESP] |
dc.subject.eng.fl_str_mv |
Myoglobin Acetoacetate 2-Methylacetoacetate Free radicals Triplet carbonyls Methylglyoxal Diacetyl Ketosis |
topic |
Myoglobin Acetoacetate 2-Methylacetoacetate Free radicals Triplet carbonyls Methylglyoxal Diacetyl Ketosis |
description |
Acetoacetate (AA) and 2-methylacetoacetate (MAA) are accumulated in metabolic disorders such as diabetes and isoleucinemia. Here we examine the mechanism of AA and MAA aerobic oxidation initiated by myoglobin (Mb)/H2O2. We propose a chemiluminescent route involving a dioxetanone intermediate whose thermolysis yields triplet alpha-dicarbonyl species (methylglyoxal and diacetyl). the observed ultraweak chemiluminescence increased linearly on raising the concentration of either Mb (10-500 mu M) or AA (10-100 mM). Oxygen uptake studies revealed that MAA is almost a 100-fold more reactive than AA. EPR spin-trapping studies with MNP/MAA revealed the intermediacy of an alpha-carbon-centered radical and acetyl radical. the latter radical, probably derived from triplet diacetyl, is totally suppressed by sorbate, a well-known quencher of triplet carbonyls. Furthermore, an EPR signal assignable to MNP-AA(center dot) adduct was observed and confirmed by isotope effects. Oxygen consumption and a-dicarbonyl yield were shown to be dependent on AA or MAA concentrations (1-50 mM) and on H2O2 or tert-butOOH added to the Mb-containing reaction mixtures. That ferrylMb is involved in a peroxidase cycle acting on the substrates is suggested by the reaction pH profiles and immunospin-trapping experiments. the generation of radicals and triplet dicarbonyl products by Mb/H2O2/beta-ketoacids may contribute to the adverse health effects of ketogenic unbalance. (C) 2011 Elsevier Inc. All rights reserved. |
publishDate |
2011 |
dc.date.issued.fl_str_mv |
2011-08-01 |
dc.date.accessioned.fl_str_mv |
2016-01-24T14:17:01Z |
dc.date.available.fl_str_mv |
2016-01-24T14:17:01Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
Free Radical Biology and Medicine. New York: Elsevier B.V., v. 51, n. 3, p. 733-743, 2011. |
dc.identifier.uri.fl_str_mv |
http://repositorio.unifesp.br/handle/11600/33896 http://dx.doi.org/10.1016/j.freeradbiomed.2011.05.002 |
dc.identifier.issn.none.fl_str_mv |
0891-5849 |
dc.identifier.file.none.fl_str_mv |
WOS000292856900017.pdf |
dc.identifier.doi.none.fl_str_mv |
10.1016/j.freeradbiomed.2011.05.002 |
dc.identifier.wos.none.fl_str_mv |
WOS:000292856900017 |
identifier_str_mv |
Free Radical Biology and Medicine. New York: Elsevier B.V., v. 51, n. 3, p. 733-743, 2011. 0891-5849 WOS000292856900017.pdf 10.1016/j.freeradbiomed.2011.05.002 WOS:000292856900017 |
url |
http://repositorio.unifesp.br/handle/11600/33896 http://dx.doi.org/10.1016/j.freeradbiomed.2011.05.002 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.none.fl_str_mv |
Free Radical Biology and Medicine |
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http://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
http://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy |
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openAccess |
dc.format.none.fl_str_mv |
733-743 |
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Elsevier B.V. |
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Elsevier B.V. |
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