Pyridyloxobutyl Adduct <i>O</i><sup>6</sup>-[4-Oxo-4-(3-pyridyl)butyl]guanine Is Present in 4-(Acetoxymethylnitrosamino)-1-(3-pyridyl)-1-butanone-Treated DNA and Is a Substrate for <i>O</i><sup>6</sup>-Alkylguanine-DNA Alkyltransferase
作者:Lijuan Wang、Thomas E. Spratt、Xiao-Keng Liu、Stephen S. Hecht、Anthony E. Pegg、Lisa A. Peterson
DOI:10.1021/tx9602067
日期:1997.5.1
prepared. This adduct was stable at pH 7.0 for greater than 13 days and to neutral thermal hydrolysis conditions (pH 7.0, 100 degrees C, 30 min). Under mild acid hydrolysis conditions (0.1 N HCl, 80 degrees C), O6-pobdG was depurinated to yield O6-[4-oxo-4-(3-pyridyl)butyl]guanine (O6-pobG). O6-pobdG was hydrolyzed to 4-hydroxy-1-(3-pyridyl)-1-butanone and guanine under strong acid hydrolysis conditions
肺致癌物4-(甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮(NNK)被活化为甲基化或吡啶基氧代丁基化DNA的反应性代谢产物。先前的研究表明,吡啶基氧代丁基化的DNA会干扰O6-烷基鸟嘌呤-DNA烷基转移酶(AGT)对O6-甲基鸟嘌呤(O6-mG)的修复。吡啶基氧代丁基化DNA的AGT反应性归因于(吡啶基氧代丁基)鸟嘌呤加合物。制备了一种潜在的AGT底物加合物2'-脱氧-O6- [4-氧代-4-(3-吡啶基)丁基]鸟苷(O6-pobdG)。该加合物在pH 7.0稳定超过13天,并在中性热水解条件(pH 7.0,100摄氏度,30分钟)下稳定。在温和的酸水解条件下(0.1 N HCl,80摄氏度),将O6-pobdG脱嘌呤化,以生成O6- [4-氧代-4-(3-吡啶基)丁基]鸟嘌呤(O6-pobG)。在强酸水解条件(0.8 N HCl,80摄氏度)下,O6-pobdG水解为4-羟基-1-(3-