Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, and Environmental Health Sciences Program, School of Public Health, University of Alberta, 10-102 Clinical Science Building, Edmonton, Alberta, Canada T6G 2G3.
Environ Sci Technol. 2010 Dec 15;44(24):9557-63. doi: 10.1021/es1024492. Epub 2010 Nov 11.
Four halobenzoquinones, 2,6-dibromo-1,4-benzoquinone, 2,6-dichloro-1,4-benzoquinone, 2,6-dichloro-3-methyl-1,4-benzoquinone, and 2,3,6-trichloro-1,4-benzoquinone, were recently identified as drinking water disinfection byproducts. Understanding their interactions with biomolecules could provide useful insights into their potential toxic effects. We report here electrospray ionization mass spectrometry characterization of the interactions between these new halobenzoquinone disinfection byproducts and oligodeoxynucleotides. The study demonstrates that 2,6-dibromo-1,4-benzoquinone exhibits much stronger binding to single- and double-stranded oligodeoxynucleotides than chlorobenzoquinones. The binding affinity of 2,6-dibromo-1,4-benzoquinone to oligodeoxynucleotides is similar to that of ethidium bromide, a well-known intercalator and carcinogen. Tandem mass spectrometry characterization confirms the formation of 1:1 and 2:1 complexes of 2,6-dibromo-1,4-benzoquinone binding to oligodeoxynucleotides. Collision-induced dissociation analysis of these adducts demonstrates neutral loss and charge separation, suggesting that 2,6-dibromo-1,4-benzoquinone binds to oligodeoxynucleotides through partial intercalation and H-bonding modes. The three chlorobezoquinones also form 1:1 adducts with the oligodeoxynucleotides, but their binding to the oligodeoxynucleotides was much weaker compared to that of 2,6-dibromo-1,4-benzoquinone. The relative binding affinity of the studied disinfection byproducts to oligodeoxynucleotides is in the order of 2,6-dibromo-1,4-benzoquinone≫2,6-dichloro-1,4-benzoquinone > 2,6-dichloro-3-methyl-1,4-benzoquinone ∼ 2,3,6-trichloro-1,4-benzoquinone, indicating potential structural effects on the interactions of halobenzoquinones with oligodeoxynucleotides.
四种卤代苯醌，2,6-二溴-1,4-苯醌、2,6-二氯-1,4-苯醌、2,6-二氯-3-甲基-1,4-苯醌和 2,3,6-三氯-1,4-苯醌，最近被确定为饮用水消毒副产物。了解它们与生物分子的相互作用可以为它们的潜在毒性效应提供有用的见解。我们在这里报告了这些新的卤代苯醌消毒副产物与寡脱氧核苷酸相互作用的电喷雾电离质谱表征。该研究表明，2,6-二溴-1,4-苯醌与单链和双链寡脱氧核苷酸的结合比氯代苯醌强得多。2,6-二溴-1,4-苯醌与寡脱氧核苷酸的结合亲和力与乙锭溴化物相似，乙锭溴化物是一种众所周知的嵌入剂和致癌物。串联质谱表征证实了 2,6-二溴-1,4-苯醌与寡脱氧核苷酸形成 1:1 和 2:1 复合物。这些加合物的碰撞诱导解离分析表明存在中性损失和电荷分离，表明 2,6-二溴-1,4-苯醌通过部分嵌入和氢键结合模式与寡脱氧核苷酸结合。三种氯代苯醌也与寡脱氧核苷酸形成 1:1 加合物，但与 2,6-二溴-1,4-苯醌相比，它们与寡脱氧核苷酸的结合较弱。所研究的消毒副产物对寡脱氧核苷酸的相对结合亲和力顺序为 2,6-二溴-1,4-苯醌≫2,6-二氯-1,4-苯醌＞2,6-二氯-3-甲基-1,4-苯醌～2,3,6-三氯-1,4-苯醌，表明卤代苯醌与寡脱氧核苷酸相互作用存在潜在的结构效应。
