Formation of compound I in the reaction of native myoglobins with hydrogen peroxide

Tsuyoshi Egawa, Hideo Shimada, Yuzuru Ishimura

Research output: Contribution to journalArticle

95 Citations (Scopus)

Abstract

Reaction of ferric native myoglobin (Mb) with hydrogen peroxide (H2O2) was studied by the aid of stopped-flow rapid-scan spectrophotometry. In contrast to the results in previous studies where compound I was reported to be undetectable, both sperm whale and horse heart metmyoglobins (metMbs) formed a significant quantity of compound I, an oxoferryl porphyrln π-cation radical (Por+-Fe (IV)(O)), during their reactions with H2O2. With both kinds of Mbs, formation of compound I was more clearly observed in D2O than in H2O. The compound thus formed was capable of performing monooxygenation of thioanisole to methyl phenyl sulfoxide and a 2-electron oxidation of H2O2 giving O2 and H2O as products. It was also converted into ferryl myoglobin (Por-Fe (IV)(O)-globin+) spontaneously. Rate constants for these reactions and that for a direct conversion of metMb to ferryl Mb through the homolysis of H2O2 were determined. These results established unambiguously that native metMb can form both compound I and ferryl Mb upon reaction with H2O2 and that these high valent iron compounds serve as essential intermediates in Mb-assisted peroxidative reactions. The observed deuterium effect on the apparent stability of compound I was attributable to that effect on the hydrogen abstraction step in the 2-electron oxidation of H2O2 by compound I.

Original languageEnglish (US)
Pages (from-to)34858-34866
Number of pages9
JournalJournal of Biological Chemistry
Volume275
Issue number45
DOIs
StatePublished - Nov 10 2000
Externally publishedYes

Fingerprint

Myoglobin
Hydrogen Peroxide
Sperm Whale
Metmyoglobin
Iron Compounds
Electrons
Oxidation
Globins
Deuterium
Spectrophotometry
Horses
Cations
Hydrogen
Rate constants

ASJC Scopus subject areas

  • Biochemistry

Cite this

Formation of compound I in the reaction of native myoglobins with hydrogen peroxide. / Egawa, Tsuyoshi; Shimada, Hideo; Ishimura, Yuzuru.

In: Journal of Biological Chemistry, Vol. 275, No. 45, 10.11.2000, p. 34858-34866.

Research output: Contribution to journalArticle

Egawa, Tsuyoshi ; Shimada, Hideo ; Ishimura, Yuzuru. / Formation of compound I in the reaction of native myoglobins with hydrogen peroxide. In: Journal of Biological Chemistry. 2000 ; Vol. 275, No. 45. pp. 34858-34866.
@article{800799bd6d2c4da8897fa52f759d7b97,
title = "Formation of compound I in the reaction of native myoglobins with hydrogen peroxide",
abstract = "Reaction of ferric native myoglobin (Mb) with hydrogen peroxide (H2O2) was studied by the aid of stopped-flow rapid-scan spectrophotometry. In contrast to the results in previous studies where compound I was reported to be undetectable, both sperm whale and horse heart metmyoglobins (metMbs) formed a significant quantity of compound I, an oxoferryl porphyrln π-cation radical (Por+-Fe (IV)(O)), during their reactions with H2O2. With both kinds of Mbs, formation of compound I was more clearly observed in D2O than in H2O. The compound thus formed was capable of performing monooxygenation of thioanisole to methyl phenyl sulfoxide and a 2-electron oxidation of H2O2 giving O2 and H2O as products. It was also converted into ferryl myoglobin (Por-Fe (IV)(O)-globin+) spontaneously. Rate constants for these reactions and that for a direct conversion of metMb to ferryl Mb through the homolysis of H2O2 were determined. These results established unambiguously that native metMb can form both compound I and ferryl Mb upon reaction with H2O2 and that these high valent iron compounds serve as essential intermediates in Mb-assisted peroxidative reactions. The observed deuterium effect on the apparent stability of compound I was attributable to that effect on the hydrogen abstraction step in the 2-electron oxidation of H2O2 by compound I.",
author = "Tsuyoshi Egawa and Hideo Shimada and Yuzuru Ishimura",
year = "2000",
month = "11",
day = "10",
doi = "10.1074/jbc.M004026200",
language = "English (US)",
volume = "275",
pages = "34858--34866",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "45",

}

TY - JOUR

T1 - Formation of compound I in the reaction of native myoglobins with hydrogen peroxide

AU - Egawa, Tsuyoshi

AU - Shimada, Hideo

AU - Ishimura, Yuzuru

PY - 2000/11/10

Y1 - 2000/11/10

N2 - Reaction of ferric native myoglobin (Mb) with hydrogen peroxide (H2O2) was studied by the aid of stopped-flow rapid-scan spectrophotometry. In contrast to the results in previous studies where compound I was reported to be undetectable, both sperm whale and horse heart metmyoglobins (metMbs) formed a significant quantity of compound I, an oxoferryl porphyrln π-cation radical (Por+-Fe (IV)(O)), during their reactions with H2O2. With both kinds of Mbs, formation of compound I was more clearly observed in D2O than in H2O. The compound thus formed was capable of performing monooxygenation of thioanisole to methyl phenyl sulfoxide and a 2-electron oxidation of H2O2 giving O2 and H2O as products. It was also converted into ferryl myoglobin (Por-Fe (IV)(O)-globin+) spontaneously. Rate constants for these reactions and that for a direct conversion of metMb to ferryl Mb through the homolysis of H2O2 were determined. These results established unambiguously that native metMb can form both compound I and ferryl Mb upon reaction with H2O2 and that these high valent iron compounds serve as essential intermediates in Mb-assisted peroxidative reactions. The observed deuterium effect on the apparent stability of compound I was attributable to that effect on the hydrogen abstraction step in the 2-electron oxidation of H2O2 by compound I.

AB - Reaction of ferric native myoglobin (Mb) with hydrogen peroxide (H2O2) was studied by the aid of stopped-flow rapid-scan spectrophotometry. In contrast to the results in previous studies where compound I was reported to be undetectable, both sperm whale and horse heart metmyoglobins (metMbs) formed a significant quantity of compound I, an oxoferryl porphyrln π-cation radical (Por+-Fe (IV)(O)), during their reactions with H2O2. With both kinds of Mbs, formation of compound I was more clearly observed in D2O than in H2O. The compound thus formed was capable of performing monooxygenation of thioanisole to methyl phenyl sulfoxide and a 2-electron oxidation of H2O2 giving O2 and H2O as products. It was also converted into ferryl myoglobin (Por-Fe (IV)(O)-globin+) spontaneously. Rate constants for these reactions and that for a direct conversion of metMb to ferryl Mb through the homolysis of H2O2 were determined. These results established unambiguously that native metMb can form both compound I and ferryl Mb upon reaction with H2O2 and that these high valent iron compounds serve as essential intermediates in Mb-assisted peroxidative reactions. The observed deuterium effect on the apparent stability of compound I was attributable to that effect on the hydrogen abstraction step in the 2-electron oxidation of H2O2 by compound I.

UR - http://www.scopus.com/inward/record.url?scp=0034634543&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034634543&partnerID=8YFLogxK

U2 - 10.1074/jbc.M004026200

DO - 10.1074/jbc.M004026200

M3 - Article

C2 - 10945982

AN - SCOPUS:0034634543

VL - 275

SP - 34858

EP - 34866

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 45

ER -