Specific role of taurine in the 8-brominated-2'-deoxyguanosine formation.
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.
['Asahi|Takashi|T|', 'Nakamura|Yoshimasa|Y|', 'Kato|Yoji|Y|', 'Osawa|Toshihiko|T|']
D000818:Animals D001959:Bromates D002851:Chromatography, High Pressure Liquid D003849:Deoxyguanosine D054879:Halogenation D006801:Humans D006997:Hypochlorous Acid D066298:In Vitro Techniques D007249:Inflammation D009195:Peroxidase D053719:Tandem Mass Spectrometry D013654:Taurine
Taurine Hypobromous acid Bromamine Nicotine 8-bromo-2′-deoxyguanosine