Inducible nitric oxide synthase catalyzes ethanol oxidation to alpha-hydroxyethyl radical and acetaldehyde.
The physiologic function of nitric oxide synthases, independent of the isozyme, is well established, metabolizing L-arginine to L-citrulline and nitric oxide (NO). This enzyme can also transfer electrons to O2, affording superoxide (O2*-) and hydrogen peroxide (H2O2). We have demonstrated that NOS1, in the presence of L-arginine, can biotransform ethanol (EtOH) to alpha-hydroxyethyl radical (CH3*CHOH). We now report that a competent NOS2 with l-arginine can, like NOS1, oxidize EtOH to CH3*CHOH. Once this free radical is formed, it is metabolized to acetaldehyde as shown by LC-ESI-MS/MS and HPLC analysis. These observations suggest that NOS2 can behave similarly to cytochrome P-450 in the catalysis of acetaldehyde formation from ethanol via the generation of alpha-hydroxyethyl radical when L-arginine is present.
Porasuphatana
Supatra
S
Department of Toxicology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand. psupatra@kku.ac.th
Weaver
John
J
Rosen
Gerald M
GM
D000079:Acetaldehyde / Q000737:chemistry*; D001120:Arginine / Q000737:chemistry; D002374:Catalase / Q000737:chemistry; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D000431:Ethanol / Q000737:chemistry*; D006835:Hydrazones / Q000737:chemistry; D052247:Nitric Oxide Synthase Type II / Q000737:chemistry*; D010084:Oxidation-Reduction; D021241:Spectrometry, Mass, Electrospray Ionization; D019097:Spin Trapping; D013482:Superoxide Dismutase / Q000737:chemistry
C001072:2,4-dinitrophenylhydrazone; D006835:Hydrazones; C065424:1-hydroxyethyl radical; D000431:Ethanol; D001120:Arginine; D002374:Catalase; D052247:Nitric Oxide Synthase Type II; D013482:Superoxide Dismutase; D000079:Acetaldehyde