Regulation of the monomer-dimer equilibrium in inducible nitric-oxide synthase by nitric oxide

David Li, Eric Y. Hayden, Koustubh Panda, Dennis J. Stuehr, Haiteng Deng, Denis L. Rousseau, Syun-Ru Yeh

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

The oxygenase domain of inducible nitric-oxide synthase exists as a functional tight homodimer in the presence of the substrate L-arginine and the cofactor tetrahydrobiopterin (H4B). In the absence of H4B, the enzyme is a mixture of monomer and loose dimer. We show that exposure of H4B-free enzyme to NO induces dissociation of the loose dimer into monomers in a reaction that follows single exponential decay kinetics with a lifetime of ∼300 min. It is followed by a faster autoreduction reaction of the heme iron with a lifetime of ∼30 min and the concurrent breakage of the proximal iron-thiolate bond, forming a five-coordinate NO-bound ferrous species. Mass spectrometry revealed that the NO-induced monomerization is associated with intramolecular disulfide bond formation between Cys104 and Cys109, located in the zinc-binding motif. The regulatory effect of NO as a dimer inhibitor is discussed in the context of the structure/function relationships of this enzyme.

Original languageEnglish (US)
Pages (from-to)8197-8204
Number of pages8
JournalJournal of Biological Chemistry
Volume281
Issue number12
DOIs
StatePublished - Mar 24 2006

Fingerprint

Nitric Oxide Synthase Type II
Dimers
Nitric Oxide
Monomers
Enzymes
Iron
Oxygenases
Heme
Disulfides
Mass spectrometry
Arginine
Zinc
Mass Spectrometry
Kinetics
Substrates

ASJC Scopus subject areas

  • Biochemistry

Cite this

Regulation of the monomer-dimer equilibrium in inducible nitric-oxide synthase by nitric oxide. / Li, David; Hayden, Eric Y.; Panda, Koustubh; Stuehr, Dennis J.; Deng, Haiteng; Rousseau, Denis L.; Yeh, Syun-Ru.

In: Journal of Biological Chemistry, Vol. 281, No. 12, 24.03.2006, p. 8197-8204.

Research output: Contribution to journalArticle

Li, David ; Hayden, Eric Y. ; Panda, Koustubh ; Stuehr, Dennis J. ; Deng, Haiteng ; Rousseau, Denis L. ; Yeh, Syun-Ru. / Regulation of the monomer-dimer equilibrium in inducible nitric-oxide synthase by nitric oxide. In: Journal of Biological Chemistry. 2006 ; Vol. 281, No. 12. pp. 8197-8204.
@article{d53c6bee86d74d759b7f38e137834f19,
title = "Regulation of the monomer-dimer equilibrium in inducible nitric-oxide synthase by nitric oxide",
abstract = "The oxygenase domain of inducible nitric-oxide synthase exists as a functional tight homodimer in the presence of the substrate L-arginine and the cofactor tetrahydrobiopterin (H4B). In the absence of H4B, the enzyme is a mixture of monomer and loose dimer. We show that exposure of H4B-free enzyme to NO induces dissociation of the loose dimer into monomers in a reaction that follows single exponential decay kinetics with a lifetime of ∼300 min. It is followed by a faster autoreduction reaction of the heme iron with a lifetime of ∼30 min and the concurrent breakage of the proximal iron-thiolate bond, forming a five-coordinate NO-bound ferrous species. Mass spectrometry revealed that the NO-induced monomerization is associated with intramolecular disulfide bond formation between Cys104 and Cys109, located in the zinc-binding motif. The regulatory effect of NO as a dimer inhibitor is discussed in the context of the structure/function relationships of this enzyme.",
author = "David Li and Hayden, {Eric Y.} and Koustubh Panda and Stuehr, {Dennis J.} and Haiteng Deng and Rousseau, {Denis L.} and Syun-Ru Yeh",
year = "2006",
month = "3",
day = "24",
doi = "10.1074/jbc.M507328200",
language = "English (US)",
volume = "281",
pages = "8197--8204",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "12",

}

TY - JOUR

T1 - Regulation of the monomer-dimer equilibrium in inducible nitric-oxide synthase by nitric oxide

AU - Li, David

AU - Hayden, Eric Y.

AU - Panda, Koustubh

AU - Stuehr, Dennis J.

AU - Deng, Haiteng

AU - Rousseau, Denis L.

AU - Yeh, Syun-Ru

PY - 2006/3/24

Y1 - 2006/3/24

N2 - The oxygenase domain of inducible nitric-oxide synthase exists as a functional tight homodimer in the presence of the substrate L-arginine and the cofactor tetrahydrobiopterin (H4B). In the absence of H4B, the enzyme is a mixture of monomer and loose dimer. We show that exposure of H4B-free enzyme to NO induces dissociation of the loose dimer into monomers in a reaction that follows single exponential decay kinetics with a lifetime of ∼300 min. It is followed by a faster autoreduction reaction of the heme iron with a lifetime of ∼30 min and the concurrent breakage of the proximal iron-thiolate bond, forming a five-coordinate NO-bound ferrous species. Mass spectrometry revealed that the NO-induced monomerization is associated with intramolecular disulfide bond formation between Cys104 and Cys109, located in the zinc-binding motif. The regulatory effect of NO as a dimer inhibitor is discussed in the context of the structure/function relationships of this enzyme.

AB - The oxygenase domain of inducible nitric-oxide synthase exists as a functional tight homodimer in the presence of the substrate L-arginine and the cofactor tetrahydrobiopterin (H4B). In the absence of H4B, the enzyme is a mixture of monomer and loose dimer. We show that exposure of H4B-free enzyme to NO induces dissociation of the loose dimer into monomers in a reaction that follows single exponential decay kinetics with a lifetime of ∼300 min. It is followed by a faster autoreduction reaction of the heme iron with a lifetime of ∼30 min and the concurrent breakage of the proximal iron-thiolate bond, forming a five-coordinate NO-bound ferrous species. Mass spectrometry revealed that the NO-induced monomerization is associated with intramolecular disulfide bond formation between Cys104 and Cys109, located in the zinc-binding motif. The regulatory effect of NO as a dimer inhibitor is discussed in the context of the structure/function relationships of this enzyme.

UR - http://www.scopus.com/inward/record.url?scp=33646351050&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33646351050&partnerID=8YFLogxK

U2 - 10.1074/jbc.M507328200

DO - 10.1074/jbc.M507328200

M3 - Article

VL - 281

SP - 8197

EP - 8204

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 12

ER -