Cited by 705Nitric Oxide and Endothelin EffectsMetal-Catalyzed Oxygenation MechanismsRedox biology and oxidative stress

Superoxide Generation from Endothelial Nitric-oxide Synthase

Open access
Xia, Yong, Tsai, Ah-Lim, Berka, Vladimir, Zweier, Jay L.·1998·Journal of Biological Chemistry

Abstract

It has been previously shown that besides synthesizing nitric oxide (NO), neuronal and inducible NO synthase (NOS) generates superoxide (O-2) under conditions of L-arginine depletion. However, there is controversy regarding whether endothelial NOS (eNOS) can also produce O-2. Moreover, the mechanism and control of this process are not fully understood. Therefore, we performed electron paramagnetic resonance spin-trapping experiments to directly measure and characterize the O-2 generation from purified eNOS. With the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), prominent signals of O-2 adduct, DMPO-OOH, were detected from eNOS in the absence of added tetrahydrobiopterin (BH4), and these were quenched by superoxide dismutase. This O-2 formation required Ca2+/calmodulin and was blocked by the specific NOS inhibitor N-nitro-L-arginine methyl ester (L-NAME) but not its non-inhibitory enantiomer D-NAME. A parallel process of Ca2+/calmodulin-dependent NADPH oxidation was observed which was also inhibited by L-NAME but not D-NAME. Pretreatment of the enzyme with the heme blockers cyanide or imidazole also prevented O-2 generation. BH4 exerted dose-dependent inhibition of the O-2 signals generated by eNOS. Conversely, in the absence of BH4 L-arginine did not decrease this O-2 generation. Thus, eNOS can also catalyze O-2 formation, and this appears to occur primarily at the heme center of its oxygenase domain. O-2 synthesis from eNOS requires Ca2+/calmodulin and is primarily regulated by BH4 rather than L-arginine.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1074/jbc.273.40.25804

Cites

25 of 25 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • In recent years, it has become clear that extracellular l-arginine and ADMA concentrations, compartmentalization, and membrane transporters are important for NOS function.

    “However, in recent years, it has become clear that extracellular l-arginine and ADMA concentrations, compartmentalization, and membrane transporters are important for NOS function, as will be discussed below in sect. IIIB4 (167, 668, 1030).”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 4

  1. Xia, Y., Dawson, V. L., Dawson, T. M., Snyder, S. H., and Zweier, J. L. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 6770 -6774
  2. Xia, Y., and Zweier, J. L. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 6954 -6958
  3. Bredt, D. S., and Snyder, S. H. (1989) Proc. Natl. Acad. Sci. U. S. A. 86, 9030 -9033
  4. Xia, Y., and Zweier, J. L. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 12705-12710

Cited by

Sorted by citations

Authors
Xia, Y., Tsai, A.-L., Berka, V., & Zweier, J. L.
Affiliations
Johns Hopkins University (US)
Corresponding author
Zweier, Jay L.
Venue
Journal of Biological Chemistry
Publisher
Elsevier BV
Published
1998-10
Volume
273
Issue
40
Pages
25804-25808
ISSN
0021-9258 (ISSN-L)
OpenAlex
W2063024150
Cited by
705
References
25
Citations by year
2026: 6 · 2025: 4 · 2024: 5 · 2023: 13 · 2022: 10 · 2021: 9 · 2020: 16 · 2019: 18 · 2018: 25 · 2017: 17 · 2016: 16 · 2015: 18 · 2014: 21 · 2013: 26 · 2012: 37
FWCI
14.09
Type
journal article
Language
en
Open access
Locations
  • Journal of Biological Chemistry (publishedVersion, cc-by)
  • PubMed (publishedVersion)
Funders
  • National Heart, Lung, and Blood Institute (HL-38324, HL52315, P50HL052315)
  • National Institute of General Medical Sciences (GM-44911, R01GM044911)
Topics
  • Health Sciences › Medicine › Physiology › Nitric Oxide and Endothelin Effects
  • Physical Sciences › Chemistry › Inorganic Chemistry › Metal-Catalyzed Oxygenation Mechanisms
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Redox biology and oxidative stress
Keywords
endothelial nitric oxide synthase, superoxide production, tetrahydrobiopterin, L-arginine, calcium/calmodulin regulation, NADPH oxidation, L-NAME, superoxide dismutase, DMPO spin trapping, imidazole, cyanide
MeSH terms
Arginine, Biopterins, Calcium, Calmodulin, Cyclic N-Oxides, Electron Spin Resonance Spectroscopy, Enzyme Inhibitors, Free Radicals, Humans, NADP, Recombinant Proteins, Sodium Cyanide, Spin Labels, Stereoisomerism, Superoxides, Nitric Oxide Synthase, NG-Nitroarginine Methyl Ester

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review