Evidence map›Paper›PMID 27226593›Full record

ArticleThe Journal of biological chemistry2016

Substrate-selective Inhibition of Cyclooxygeanse-2 by Fenamic Acid Derivatives Is Dependent on Peroxide Tone.

Benjamin J Orlando, Michael G Malkowski

Open access · hybridAbstract read
In one paragraph

Article in The Journal of biological chemistry, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 86 papers.

0numbers the graph read from it
0cells of the map it votes in
86citing papers in PubMed
11.2field-weighted citation impact, top 2% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

86 citing papers in PubMed, 225 citations in OpenAlex.

  1. Trial
  2. Article
  3. Review
  4. Article
  5. Article
  6. Exploring the Anti-Inflammatory Potential ofPlants (Basel, Switzerland) · 2026
    Article
  7. Article
  8. Article
  9. Article
  10. Article
  11. Molecular and Pharmacokinetic Rationale for the Use ofMolecules (Basel, Switzerland) · 2026
    Article
  12. Article
  13. Article
  14. Article
  15. Article
  16. Anti-Inflammatory Effects of Bisacurone Isolated fromMolecules (Basel, Switzerland) · 2026
    Article
  17. Article
  18. Article
  19. Article
  20. Potential Nutraceutical Properties ofMolecules (Basel, Switzerland) · 2026
    Article

26 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors at 1 institution in 1 country.

Benjamin J OrlandoFrom the Department of Structural Biology, The State University of New York at Buffalo and.
Michael G MalkowskiFrom the Department of Structural Biology, The State University of New York at Buffalo and the Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203 mgm22@buffalo.edu.
University at Buffalo, State University of New York · US

Funding

TR&D 4 for ACERT, 2017-2021 funding periodP41GM103521 · NIGMS · CORNELL UNIVERSITY · PI FREED, JACK H · 2012 to 2021
$11.7M
Structure and Dynamics of Cyclooxygenase Catalysis and InhibitionR01GM115386 · NIGMS · STATE UNIVERSITY OF NEW YORK AT BUFFALO · PI MALKOWSKI, MICHAEL G · 2015 to 2018
$1.5M
NIGMS NIH HHS P41 GM103521NIGMS NIH HHS R01 GM115386
6 · The paper itself

Abstract

Cyclooxygenase-2 (COX-2) catalyzes the oxygenation of arachidonic acid (AA) and endocannabinoid substrates, placing the enzyme at a unique junction between the eicosanoid and endocannabinoid signaling pathways. COX-2 is a sequence homodimer, but the enzyme displays half-of-site reactivity, such that only one monomer of the dimer is active at a given time. Certain rapid reversible, competitive nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to inhibit COX-2 in a substrate-selective manner, with the binding of inhibitor to a single monomer sufficient to inhibit the oxygenation of endocannabinoids but not arachidonic acid. The underlying mechanism responsible for substrate-selective inhibition has remained elusive. We utilized structural and biophysical methods to evaluate flufenamic acid, meclofenamic acid, mefenamic acid, and tolfenamic acid for their ability to act as substrate-selective inhibitors. Crystal structures of each drug in complex with human COX-2 revealed that the inhibitor binds within the cyclooxygenase channel in an inverted orientation, with the carboxylate group interacting with Tyr-385 and Ser-530 at the top of the channel. Tryptophan fluorescence quenching, continuous-wave electron spin resonance, and UV-visible spectroscopy demonstrate that flufenamic acid, mefenamic acid, and tolfenamic acid are substrate-selective inhibitors that bind rapidly to COX-2, quench tyrosyl radicals, and reduce higher oxidation states of the heme moiety. Substrate-selective inhibition was attenuated by the addition of the lipid peroxide 15-hydroperoxyeicosatertaenoic acid. Collectively, these studies implicate peroxide tone as an important mechanistic component of substrate-selective inhibition by flufenamic acid, mefenamic acid, and tolfenamic acid.

Indexed as

Amino Acid SubstitutionBinding SitesCrystallography, X-RayCyclooxygenase 2Cyclooxygenase 2 InhibitorsEndocannabinoidsFenamatesHemeHumansIn Vitro TechniquesModels, MolecularMutagenesis, Site-DirectedPeroxidesRecombinant ProteinsSubstrate SpecificityTryptophanCyclooxygenase 2Cyclooxygenase 2 InhibitorsEndocannabinoidsFenamatesHemePeroxidesPTGS2 protein, humanRecombinant ProteinsTryptophancrystal structurecyclooxygenase (COX)electron paramagnetic resonance (EPR)endocannabinoidnonsteroidal anti-inflammatory drugsstructural biology

Identifiers

PMID27226593
PMCPMC4946924
OpenAlexW2401866878

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.