Superoxide generation by endothelial nitric oxide synthase: the influence of cofactors.
- J. Vasquez-Vivar, B. Kalyanaraman, K. Pritchard
- Biology, ChemistryProceedings of the National Academy of Sciences…
- 4 August 1998
Results demonstrate that superoxide is generated from the oxygenase domain by dissociation of the ferrous-dioxygen complex and that occupation of the L-arginine binding site does not inhibit this process, and indicate that modulation of BH4 concentration may regulate the ratio of superoxide to nitric oxide generated by eNOS.
Superoxide reacts with hydroethidine but forms a fluorescent product that is distinctly different from ethidium: potential implications in intracellular fluorescence detection of superoxide.
- Hongtao Zhao, Shasi V Kalivendi, B. Kalyanaraman
- Biology, ChemistryFree Radical Biology & Medicine
- 1 June 2003
Detection and characterization of the product of hydroethidine and intracellular superoxide by HPLC and limitations of fluorescence.
- Hongtao Zhao, J. Joseph, B. Kalyanaraman
- Biology, ChemistryProceedings of the National Academy of Sciences…
- 19 April 2005
Analysis of the fluorescence characteristics of ethidium (E(+)) and 2-OH-E(+) strongly suggests that the currently available fluorescence methodology is not suitable for quantitating intracellular O(2)(.-).
Detection of 2-hydroxyethidium in cellular systems: a unique marker product of superoxide and hydroethidine
- J. Zielonka, J. Vasquez-Vivar, B. Kalyanaraman
- BiologyNature Protocols
- 2007
The detailed protocol for quantification of 2-OH-E+, the unique product of HE/O2•− in cellular systems, is presented, which includes cell lysis, protein precipitation using acidified methanol and HPLC analysis of the lysate.
The ratio between tetrahydrobiopterin and oxidized tetrahydrobiopterin analogues controls superoxide release from endothelial nitric oxide synthase: an EPR spin trapping study.
- J. Vasquez-Vivar, P. Martásek, J. Whitsett, J. Joseph, B. Kalyanaraman
- Biology, ChemistryBiochemical Journal
- 15 March 2002
It is shown that BH(4) acts as a "redox switch", decreasing superoxide release and enhancing .NO formation from eNOS, which indicates that the ratio between oxidized and reduced BH (4) metabolites tightly regulates superoxide formation fromeNOS.
Mitochondrial Aconitase Is a Source of Hydroxyl Radical
- J. Vasquez-Vivar, B. Kalyanaraman, M. Kennedy
- ChemistryJournal of Biological Chemistry
- 12 May 2000
Evidence for the generation of ⋅OH from the reaction of m-aconitase with superoxide is provided using ESR spin trapping experiments with 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide and α-phenyl-N-tert-butylnitrone.
Mitochondria-Targeted Triphenylphosphonium-Based Compounds: Syntheses, Mechanisms of Action, and Therapeutic and Diagnostic Applications.
- J. Zielonka, J. Joseph, B. Kalyanaraman
- Biology, ChemistryChemical Reviews
- 27 June 2017
The physicochemical basis for mitochondrial accumulation of lipophilic cations, synthetic chemistry strategies to target compounds to mitochondria, mitochondrial probes, and sensors, and examples of mitochondrial targeting of bioactive compounds are described.
Endothelial nitric oxide synthase-dependent superoxide generation from adriamycin.
- J. Vasquez-Vivar, P. Martásek, N. Hogg, B. Masters, K. Pritchard, B. Kalyanaraman
- Biology, ChemistryBiochemistry
- 23 September 1997
It is demonstrated here that the endothelial isoform of nitric oxide synthase (eNOS) reduces adriamycin to the semiquinone radical, which enhances superoxide formation and Nitric oxide production and leads eNOS to generate peroxynitrite and hydrogen peroxide, potent oxidants implicated in several vascular pathologies.
Detection of superoxide anion using an isotopically labeled nitrone spin trap: potential biological applications
- H. Zhang, J. Joseph, B. Kalyanaraman
- ChemistryFEBS Letters
- 4 May 2000
The Role of Tetrahydrobiopterin in Superoxide Generation from eNOS: Enzymology and Physiological Implications
- J. Vasquez-Vivar, B. Kalyanaraman, P. Martásek
- Biology, ChemistryFree radical research
- 1 January 2003
The mechanism by which BH 4 inhibits superoxide release from eNOS and the "uncoupling" effects of oxidized BH4 metabolites are presented and the implications are discussed in the light of clinical data indicating that BH 3 levels are important in the regulation of superoxide levels and of endothelial reactivity.
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