title: Specific role of taurine in the 8-brominated-2'-deoxyguanosine formation.
abstract: At the sites of inflammation, hypohalous acids, such as hypochlorous acid and hypobromous acid (HOBr), are produced by myeloperoxidase. These hypohalous acids rapidly react with the primary amino groups to produce haloamines, which are relatively stable and can diffuse long distances and cross the plasma membrane. In this study, we examined the effects of taurine, the most abundant free amino acid in the leukocyte cytosol, on the hypohalous acid-dependent formation of 8-chloro-2'-deoxyguanosine (8-CldG) and 8-bromo-2'-deoxyguanosine (8-BrdG). The reaction of taurine with HOBr yielded taurine bromamine, which is the most stable among other bromamines of amino acids. Taurine also enhanced the bromination of only dG among the four 2'-deoxynucleosides, whereas it inhibited the 8-CldG formation. The specificity of taurine for the enhanced formation of halogenated dG is completely different from that of nicotine, an enhancer of chlorination. The amount of dibrominated taurine (taurine dibromamine) closely correlated with the formation of 8-BrdG, suggesting that taurine dibromamine might be a plausible mediator for the dG bromination in vivo.
authors.affiliation: Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan; Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Asahi
authors.affiliation: Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530, Japan. Electronic address: yossan@cc.okayama-u.ac.jp.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: School of Human Science and Environment, University of Hyogo, Himeji 670-0092, Japan. Electronic address: yojikato@shse.u-hyogo.ac.jp.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Osawa
mesh_terms: D000818:Animals; D001959:Bromates / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000737:chemistry; D054879:Halogenation; D006801:Humans; D006997:Hypochlorous Acid / Q000737:chemistry / Q000378:metabolism; D066298:In Vitro Techniques; D007249:Inflammation / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D013654:Taurine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism*
chemical_list: C439365:8-bromo-2'-deoxyguanosine; C506093:8-chloro-2'-deoxyguanosine; D001959:Bromates; D013654:Taurine; D006997:Hypochlorous Acid; D009195:Peroxidase; D003849:Deoxyguanosine; C027664:hypobromous acid
keywords: 8-bromo-2′-deoxyguanosine; Bromamine; Hypobromous acid; Nicotine; Taurine