Reaction Intermediates in Oxygen Activation Reactions by Enzymes Containing Carboxylate-Bridged Binuclear Iron Clusters

Boi Hanh Huynh, Joseph M. Bollinger, Jr., Dale E. Edmondson

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The rapid freeze-quench method was used to trap intermediates in the reaction of O2 with the dinuclear iron(II) clusters in the soluble methane monooxygenase from Methylococcus capsulatus (Bath) and in the R2 subunit of the ribonucleotide reductase from Escherichia coli. Mössbauer and EPR spectroscopies were used to characterize the trapped intermediates. For methane monooxygenase, the initial intermediate formed is a peroxodiiron(III) complex which undergoes further structural and electron reorganization to form a high-valent, formally diiron(IV), complex termed Q. In the case of R2, reaction of O2 with the diiron(II) center in the presence of reducing agents generates a mixed valent, formally Fe(III), Fe(IV), complex termed X, which is capable of oxidizing the proximal Y122 to its radical form with formation of the resting diiron(III) cluster. In this chapter, spectroscopic characteristics of these intermediates are presented. Structural and mechanistic implications are also discussed.

Original languageEnglish (US)
Pages (from-to)403-422
Number of pages20
JournalACS Symposium Series
Volume692
StatePublished - Dec 1 1998

Fingerprint

methane monooxygenase
Reaction intermediates
Methane
Iron
Enzymes
Chemical activation
Oxygen
Reducing Agents
Reducing agents
Escherichia coli
Paramagnetic resonance
Spectroscopy
Electrons

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)

Cite this

@article{a7931988b0674af38243f6a01d39593e,
title = "Reaction Intermediates in Oxygen Activation Reactions by Enzymes Containing Carboxylate-Bridged Binuclear Iron Clusters",
abstract = "The rapid freeze-quench method was used to trap intermediates in the reaction of O2 with the dinuclear iron(II) clusters in the soluble methane monooxygenase from Methylococcus capsulatus (Bath) and in the R2 subunit of the ribonucleotide reductase from Escherichia coli. M{\"o}ssbauer and EPR spectroscopies were used to characterize the trapped intermediates. For methane monooxygenase, the initial intermediate formed is a peroxodiiron(III) complex which undergoes further structural and electron reorganization to form a high-valent, formally diiron(IV), complex termed Q. In the case of R2, reaction of O2 with the diiron(II) center in the presence of reducing agents generates a mixed valent, formally Fe(III), Fe(IV), complex termed X, which is capable of oxidizing the proximal Y122 to its radical form with formation of the resting diiron(III) cluster. In this chapter, spectroscopic characteristics of these intermediates are presented. Structural and mechanistic implications are also discussed.",
author = "Huynh, {Boi Hanh} and {Bollinger, Jr.}, {Joseph M.} and Edmondson, {Dale E.}",
year = "1998",
month = "12",
day = "1",
language = "English (US)",
volume = "692",
pages = "403--422",
journal = "ACS Symposium Series",
issn = "0097-6156",
publisher = "American Chemical Society",

}

Reaction Intermediates in Oxygen Activation Reactions by Enzymes Containing Carboxylate-Bridged Binuclear Iron Clusters. / Huynh, Boi Hanh; Bollinger, Jr., Joseph M.; Edmondson, Dale E.

In: ACS Symposium Series, Vol. 692, 01.12.1998, p. 403-422.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Reaction Intermediates in Oxygen Activation Reactions by Enzymes Containing Carboxylate-Bridged Binuclear Iron Clusters

AU - Huynh, Boi Hanh

AU - Bollinger, Jr., Joseph M.

AU - Edmondson, Dale E.

PY - 1998/12/1

Y1 - 1998/12/1

N2 - The rapid freeze-quench method was used to trap intermediates in the reaction of O2 with the dinuclear iron(II) clusters in the soluble methane monooxygenase from Methylococcus capsulatus (Bath) and in the R2 subunit of the ribonucleotide reductase from Escherichia coli. Mössbauer and EPR spectroscopies were used to characterize the trapped intermediates. For methane monooxygenase, the initial intermediate formed is a peroxodiiron(III) complex which undergoes further structural and electron reorganization to form a high-valent, formally diiron(IV), complex termed Q. In the case of R2, reaction of O2 with the diiron(II) center in the presence of reducing agents generates a mixed valent, formally Fe(III), Fe(IV), complex termed X, which is capable of oxidizing the proximal Y122 to its radical form with formation of the resting diiron(III) cluster. In this chapter, spectroscopic characteristics of these intermediates are presented. Structural and mechanistic implications are also discussed.

AB - The rapid freeze-quench method was used to trap intermediates in the reaction of O2 with the dinuclear iron(II) clusters in the soluble methane monooxygenase from Methylococcus capsulatus (Bath) and in the R2 subunit of the ribonucleotide reductase from Escherichia coli. Mössbauer and EPR spectroscopies were used to characterize the trapped intermediates. For methane monooxygenase, the initial intermediate formed is a peroxodiiron(III) complex which undergoes further structural and electron reorganization to form a high-valent, formally diiron(IV), complex termed Q. In the case of R2, reaction of O2 with the diiron(II) center in the presence of reducing agents generates a mixed valent, formally Fe(III), Fe(IV), complex termed X, which is capable of oxidizing the proximal Y122 to its radical form with formation of the resting diiron(III) cluster. In this chapter, spectroscopic characteristics of these intermediates are presented. Structural and mechanistic implications are also discussed.

UR - http://www.scopus.com/inward/record.url?scp=0346392093&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0346392093&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0346392093

VL - 692

SP - 403

EP - 422

JO - ACS Symposium Series

JF - ACS Symposium Series

SN - 0097-6156

ER -