A novel phosphorylated spin trap, 5-diethoxyphosphoryl-5-methyl 1-pyrroline N-oxide (DEPMPO), was used to monitor superoxide formation from purified endothelial nitric oxide synthase (eNOS). eNOS consists of a flavin-containing reductase domain and a heme-containing oxidase domain that binds L-arginine. eNOS-dependent superoxide formation can be stimulated by redox cycling agents such as lucigenin or paraquat. The reductase domain is responsible for superoxide formed from these compounds. The superoxide adduct of DEPMPO is 15 times more stable than that of the more commonly used spin trap, DMPO. Moreover, unlike the DMPO-superoxide adduct, the DEPMPO-superoxide adduct does not spontaneously decay to the DEPMPO-hydroxyl adduct. Consequently, the steady-state level of the DEPMPO-superoxide adduct is higher than the DMPO-superoxide adduct at the same rate of superoxide generation. Thus, ESR spin trapping with DEPMPO using a loop-gap resonator is a viable approach to detect superoxide formation from eNOS-dependent bioactivation of xenobiotics. ?

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR001008-23
Application #
6279859
Study Section
Project Start
1998-04-01
Project End
1999-02-28
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
23
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Medical College of Wisconsin
Department
Type
DUNS #
073134603
City
Milwaukee
State
WI
Country
United States
Zip Code
53226
Mao, Li; Liu, Yu-Xiang; Huang, Chun-Hua et al. (2015) Intrinsic Chemiluminescence Generation during Advanced Oxidation of Persistent Halogenated Aromatic Carcinogens. Environ Sci Technol 49:7940-7
Shan, Guo-Qiang; Yu, Ao; Zhao, Chuan-Fang et al. (2015) A combined experimental and computational investigation on the unusual molecular mechanism of the Lossen rearrangement reaction activated by carcinogenic halogenated quinones. J Org Chem 80:180-9
Li, Yan; Huang, Chun-Hua; Liu, Yu-Xiang et al. (2014) Detoxifying polyhalogenated catechols through a copper-chelating agent by forming stable and redox-inactive hydrogen-bonded complexes with an unusual perpendicular structure. Chemistry 20:13028-33
Sheng, Zhi-Guo; Huang, Wei; Liu, Yu-Xiang et al. (2013) Ofloxacin induces apoptosis via ?1 integrin-EGFR-Rac1-Nox2 pathway in microencapsulated chondrocytes. Toxicol Appl Pharmacol 267:74-87
Sheng, Zhi-Guo; Huang, Wei; Liu, Yu-Xiang et al. (2013) Bisphenol A at a low concentration boosts mouse spermatogonial cell proliferation by inducing the G protein-coupled receptor 30 expression. Toxicol Appl Pharmacol 267:88-94
Shao, Jie; Huang, Chun-Hua; Kalyanaraman, Balaraman et al. (2013) Potent methyl oxidation of 5-methyl-2'-deoxycytidine by halogenated quinoid carcinogens and hydrogen peroxide via a metal-independent mechanism. Free Radic Biol Med 60:177-82
Sheng, Zhi-Guo; Li, Yan; Fan, Rui-Mei et al. (2013) Lethal synergism between organic and inorganic wood preservatives via formation of an unusual lipophilic ternary complex. Toxicol Appl Pharmacol 266:335-44
Qin, Hao; Huang, Chun-Hua; Mao, Li et al. (2013) Molecular mechanism of metal-independent decomposition of lipid hydroperoxide 13-HPODE by halogenated quinoid carcinogens. Free Radic Biol Med 63:459-66
Huang, Chun-Hua; Shan, Guo-Qiang; Mao, Li et al. (2013) The first purification and unequivocal characterization of the radical form of the carbon-centered quinone ketoxy radical adduct. Chem Commun (Camb) 49:6436-8
Liddle, Brendan J; Wanniarachchi, Sarath; Hewage, Jeewantha S et al. (2012) Electronic communication across diamagnetic metal bridges: a homoleptic gallium(III) complex of a redox-active diarylamido-based ligand and its oxidized derivatives. Inorg Chem 51:12720-8

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