Dose dependent effects of reactive oxygen and nitrogen species on the function of neuronal nitric oxide synthase

Jian Sun, Lawrence J. Druhan, Jay L. Zweier

Research output: Contribution to journalArticle

Abstract

Reactive nitrogen species (RNS) and oxygen species (ROS) have been reported to modulate the function of nitric oxide synthase (NOS); however, the precise dose-dependent effects of specific RNS and ROS on NOS function are unknown. Questions remain unanswered regarding whether pathophysiological levels of RNS and ROS alter NOS function, and if this alteration is reversible. We measured the effects of peroxynitrite (ONOO-), superoxide (O2· -), hydroxyl radical (.OH), and H2O2 on nNOS activity. The results showed that NO production was inhibited in a dose-dependent manner by all four oxidants, but only O2· - and ONOO- were inhibitory at pathophysiological concentrations (≤50 μM). Subsequent addition of tetrahydrobiopterin (BH4) fully restored activity after O2· - exposure, while BH4 partially rescued the activity decrease induced by the other three oxidants. Furthermore, treatment with either ONOO- or O2· - stimulated nNOS uncoupling with decreased NO and enhanced O2· - generation. Thus, nNOS is reversibly uncoupled by O2· - (≤50 μM), but irreversibly uncoupled and inactivated by ONOO-. Additionally, we observed that the mechanism by which oxidative stress alters nNOS activity involves not only BH4 oxidation, but also nNOS monomerization as well as possible degradation of the heme.

Original languageEnglish (US)
Pages (from-to)126-133
Number of pages8
JournalArchives of Biochemistry and Biophysics
Volume471
Issue number2
DOIs
StatePublished - Mar 15 2008
Externally publishedYes

Fingerprint

Reactive Nitrogen Species
Nitric Oxide Synthase Type I
Nitric Oxide Synthase
Reactive Oxygen Species
Oxygen
Oxidants
Peroxynitrous Acid
Oxidative stress
Heme
Superoxides
Hydroxyl Radical
Oxidative Stress
Degradation
Oxidation

Keywords

  • Dose-dependent
  • Electron paramagnetic resonance
  • Free radical
  • Hydrogen peroxide
  • Hydroxyl radical
  • Monomerization
  • Neuronal nitric oxide synthase
  • Peroxynitrite
  • Superoxide
  • Tetrahydrobiopterin

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this

Dose dependent effects of reactive oxygen and nitrogen species on the function of neuronal nitric oxide synthase. / Sun, Jian; Druhan, Lawrence J.; Zweier, Jay L.

In: Archives of Biochemistry and Biophysics, Vol. 471, No. 2, 15.03.2008, p. 126-133.

Research output: Contribution to journalArticle

@article{7bc681e34d9b407f91761caa00ac6200,
title = "Dose dependent effects of reactive oxygen and nitrogen species on the function of neuronal nitric oxide synthase",
abstract = "Reactive nitrogen species (RNS) and oxygen species (ROS) have been reported to modulate the function of nitric oxide synthase (NOS); however, the precise dose-dependent effects of specific RNS and ROS on NOS function are unknown. Questions remain unanswered regarding whether pathophysiological levels of RNS and ROS alter NOS function, and if this alteration is reversible. We measured the effects of peroxynitrite (ONOO-), superoxide (O2· -), hydroxyl radical (.OH), and H2O2 on nNOS activity. The results showed that NO production was inhibited in a dose-dependent manner by all four oxidants, but only O2· - and ONOO- were inhibitory at pathophysiological concentrations (≤50 μM). Subsequent addition of tetrahydrobiopterin (BH4) fully restored activity after O2· - exposure, while BH4 partially rescued the activity decrease induced by the other three oxidants. Furthermore, treatment with either ONOO- or O2· - stimulated nNOS uncoupling with decreased NO and enhanced O2· - generation. Thus, nNOS is reversibly uncoupled by O2· - (≤50 μM), but irreversibly uncoupled and inactivated by ONOO-. Additionally, we observed that the mechanism by which oxidative stress alters nNOS activity involves not only BH4 oxidation, but also nNOS monomerization as well as possible degradation of the heme.",
keywords = "Dose-dependent, Electron paramagnetic resonance, Free radical, Hydrogen peroxide, Hydroxyl radical, Monomerization, Neuronal nitric oxide synthase, Peroxynitrite, Superoxide, Tetrahydrobiopterin",
author = "Jian Sun and Druhan, {Lawrence J.} and Zweier, {Jay L.}",
year = "2008",
month = "3",
day = "15",
doi = "10.1016/j.abb.2008.01.003",
language = "English (US)",
volume = "471",
pages = "126--133",
journal = "Archives of Biochemistry and Biophysics",
issn = "0003-9861",
publisher = "Academic Press Inc.",
number = "2",

}

TY - JOUR

T1 - Dose dependent effects of reactive oxygen and nitrogen species on the function of neuronal nitric oxide synthase

AU - Sun, Jian

AU - Druhan, Lawrence J.

AU - Zweier, Jay L.

PY - 2008/3/15

Y1 - 2008/3/15

N2 - Reactive nitrogen species (RNS) and oxygen species (ROS) have been reported to modulate the function of nitric oxide synthase (NOS); however, the precise dose-dependent effects of specific RNS and ROS on NOS function are unknown. Questions remain unanswered regarding whether pathophysiological levels of RNS and ROS alter NOS function, and if this alteration is reversible. We measured the effects of peroxynitrite (ONOO-), superoxide (O2· -), hydroxyl radical (.OH), and H2O2 on nNOS activity. The results showed that NO production was inhibited in a dose-dependent manner by all four oxidants, but only O2· - and ONOO- were inhibitory at pathophysiological concentrations (≤50 μM). Subsequent addition of tetrahydrobiopterin (BH4) fully restored activity after O2· - exposure, while BH4 partially rescued the activity decrease induced by the other three oxidants. Furthermore, treatment with either ONOO- or O2· - stimulated nNOS uncoupling with decreased NO and enhanced O2· - generation. Thus, nNOS is reversibly uncoupled by O2· - (≤50 μM), but irreversibly uncoupled and inactivated by ONOO-. Additionally, we observed that the mechanism by which oxidative stress alters nNOS activity involves not only BH4 oxidation, but also nNOS monomerization as well as possible degradation of the heme.

AB - Reactive nitrogen species (RNS) and oxygen species (ROS) have been reported to modulate the function of nitric oxide synthase (NOS); however, the precise dose-dependent effects of specific RNS and ROS on NOS function are unknown. Questions remain unanswered regarding whether pathophysiological levels of RNS and ROS alter NOS function, and if this alteration is reversible. We measured the effects of peroxynitrite (ONOO-), superoxide (O2· -), hydroxyl radical (.OH), and H2O2 on nNOS activity. The results showed that NO production was inhibited in a dose-dependent manner by all four oxidants, but only O2· - and ONOO- were inhibitory at pathophysiological concentrations (≤50 μM). Subsequent addition of tetrahydrobiopterin (BH4) fully restored activity after O2· - exposure, while BH4 partially rescued the activity decrease induced by the other three oxidants. Furthermore, treatment with either ONOO- or O2· - stimulated nNOS uncoupling with decreased NO and enhanced O2· - generation. Thus, nNOS is reversibly uncoupled by O2· - (≤50 μM), but irreversibly uncoupled and inactivated by ONOO-. Additionally, we observed that the mechanism by which oxidative stress alters nNOS activity involves not only BH4 oxidation, but also nNOS monomerization as well as possible degradation of the heme.

KW - Dose-dependent

KW - Electron paramagnetic resonance

KW - Free radical

KW - Hydrogen peroxide

KW - Hydroxyl radical

KW - Monomerization

KW - Neuronal nitric oxide synthase

KW - Peroxynitrite

KW - Superoxide

KW - Tetrahydrobiopterin

UR - http://www.scopus.com/inward/record.url?scp=39749178017&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=39749178017&partnerID=8YFLogxK

U2 - 10.1016/j.abb.2008.01.003

DO - 10.1016/j.abb.2008.01.003

M3 - Article

VL - 471

SP - 126

EP - 133

JO - Archives of Biochemistry and Biophysics

JF - Archives of Biochemistry and Biophysics

SN - 0003-9861

IS - 2

ER -