Characterization of the Mechanism of Cytochrome P450 Reductase-Cytochrome P450-mediated Nitric Oxide and Nitrosothiol Generation from Organic Nitrates
Open accessAbstract
Mammalian cytochrome P450 reductase (CPR) and cytochrome P450 (CP) play important roles in organic nitrate bioactivation; however, the mechanism by which they convert organic nitrate to NO remains unknown. Questions remain regarding the initial precursor of NO that serves to link organic nitrate to the activation of soluble guanylyl cyclase (sGC). To characterize the mechanism of CPR-CP-mediated organic nitrate bioactivation, EPR, chemiluminescence NO analyzer, NO electrode, and immunoassay studies were performed. With rat hepatic microsomes or purified CPR, the presence of NADPH triggered organic nitrate reduction to NO2(-). The CPR flavin site inhibitor diphenyleneiodonium inhibited this NO2(-) generation, whereas the CP inhibitor clotrimazole did not. However, clotrimazole greatly inhibited NO2(-)-dependent NO generation. Therefore, CPR catalyzes organic nitrate reduction, producing nitrite, whereas CP can mediate further nitrite reduction to NO. Nitrite-dependent NO generation contributed <10% of the CPR-CP-mediated NO generation from organic nitrates; thus, NO2(-) is not the main precursor of NO. CPR-CP-mediated NO generation was largely thiol-dependent. Studies suggested that organic nitrite (R-O-NO) was produced from organic nitrate reduction by CPR. Further reaction of organic nitrite with free or microsome-associated thiols led to NO or nitrosothiol generation and thus stimulated the activation of sGC. Thus, organic nitrite is the initial product in the process of CRP-CP-mediated organic nitrate activation and is the precursor of NO and nitrosothiols, serving as the link between organic nitrate and sGC activation.
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.
Integrity signals
Registry
Cites
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.
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?
A number of proteins involved in oxidative processes at basal oxygen levels can become de facto reductases as oxygen is depleted.
“However, a number of proteins that are involved in oxidative processes at basal oxygen levels can become de facto reductases as oxygen is depleted.”
From Sources of Vascular Nitric Oxide and Reactive Oxygen Species and Their Regulation (2019) · cites this paper as [575]
The biological role of the oxygen-regulated oxidative-to-reductive transition is particularly prominent for heme- and molybdopterin-containing proteins such as hemoglobin, myoglobin, and xanthine oxidase.
“The biological role of this transition is particularly prominent in the case of heme- and molybdopterin-containing proteins such as hemoglobin (Hb), myoglobin (Mb), and xanthine oxidase (XO)”
From Sources of Vascular Nitric Oxide and Reactive Oxygen Species and Their Regulation (2019) · cites this paper as [575]
AO reduces nitrite to NO, albeit at a slower rate than XO.
“AO has been shown to reduce nitrite to NO, albeit a slower rate than XO (Table 4) (568, 575, 617, 1001).”
From Sources of Vascular Nitric Oxide and Reactive Oxygen Species and Their Regulation (2019) · cites this paper as [575]
All four mammalian molybdenum-containing enzymes (XO, AO, sulfite oxidase, and mARC) are able to reduce nitrite at different intrinsic rates.
“Subsequently, several reports have shown that all mammalian Mo-containing enzymes [XO, aldehyde oxidase (AO), sulfite oxidase, and the mitochondrial amidoxime-reducing component (mARC)] are able to reduce nitrite at different intrinsic rates (Table 4) (575, 880, 990).”
From Sources of Vascular Nitric Oxide and Reactive Oxygen Species and Their Regulation (2019) · cites this paper as [575]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
The citation lists haven’t been fetched yet
References 58 · Cited by 74
Research works printed but not linked: 4
- [1]1. Arnold, W.P. ∙ Mittal, C.K. ∙ Katsuki, S. ... Proc. Natl. Acad. Sci. U. S. A. 1977; 74:3203-3207 Crossref Scopus (1261) PubMed Google Scholar
- [2]2. Murad, F. ∙ Mittal, C.K. ∙ Arnold, W.P. ... Adv. Cyclic Nucleotide Res. 1978; 9:145-158 PubMed Google Scholar
- [3]3. Ignarro, L.J. ∙ Lippton, H. ∙ Edwards, J.C. ... J. Pharmacol. Exp. Ther. 1981; 218:739-749 Full Text (PDF) PubMed Google Scholar
- [4]4. Mellion, B.T. ∙ Ignarro, L.J. ∙ Myers, C.B. ... Mol. Pharmacol. 1983; 23:653-664
- Authors
- Li, H., Liu, X., Cui, H., Chen, Y.-R., Cardounel, A. J., & Zweier, J. L.
- Affiliations
- The Ohio State University (US)
- Corresponding author
- Li, Haitao
- Zweier, Jay L.
- Venue
- Journal of Biological Chemistry
- Publisher
- Elsevier BV
- Published
- 2006-05
- Volume
- 281
- Issue
- 18
- Pages
- 12546-12554
- ISSN
- 0021-9258 (ISSN-L)
- OpenAlex
- W2012817678
- Cited by
- 74
- References
- 58
- Citations by year
- 2026: 2 · 2025: 1 · 2024: 2 · 2023: 4 · 2022: 1 · 2021: 6 · 2020: 2 · 2019: 3 · 2018: 3 · 2017: 5 · 2016: 1 · 2015: 3 · 2014: 3 · 2013: 6 · 2012: 6
- FWCI
- 3.32
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- Locations
- Journal of Biological Chemistry (publishedVersion, cc-by)
- PubMed (publishedVersion)
- Funders
- National Heart, Lung, and Blood Institute (HL-38324, R01HL083237, R01HL063744, HL 65608, P01HL065608, HL 63744)
- Topics
- Health Sciences › Medicine › Physiology › Nitric Oxide and Endothelin Effects
- Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Pharmacogenetics and Drug Metabolism
- Physical Sciences › Chemistry › Inorganic Chemistry › Metal-Catalyzed Oxygenation Mechanisms
- Keywords
- NADPH-cytochrome P450 reductase, cytochrome P450, organic nitrates, nitric oxide production, S-nitrosothiols, nitrite, diphenyleneiodonium, clotrimazole, liver microsomes, NADPH
- MeSH terms
- Animals, Cytochrome P-450 Enzyme System, Electron Spin Resonance Spectroscopy, Guanylate Cyclase, Hydrogen-Ion Concentration, Kinetics, Microsomes, Liver, NADPH-Ferrihemoprotein Reductase, Nitrates, Nitric Oxide, Nitroso Compounds, Sulfhydryl Compounds, Rats
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
