奥克拉托克素a形成一个与碳结合的c8-deoxyguanosine核酸添加物:对基因的c8反应性的影响
Jian Dai1, Marcus W Wright, Richard A Manderville
1Department of Chemistry, Wake Forest University, Winston-Salem, North Carolina 27109, USA.
Journal of the American Chemical Society
|March 27, 2003
概括
致癌毒素Ochratoxin A (OTA) 通过与脱氧氨酸 (dG) 形成共价添加物,可以直接破坏DNA. 这一发现澄清了OTA背后的机制.
科学领域:
- 毒理学 毒理学 毒理学
- 有机化学 有机化学
- 分子生物学分子生物学
背景情况:
- 毒素A (OTA) 是一种致癌的真菌毒素,涉及到DNA损伤.
- 据认为,OTA的变异性和致癌性涉及氧化DNA损伤和瓜宁特异性添加物.
研究的目的:
- 为了研究Ochratoxin A (OTA) 和deoxyguanosine (dG) 之间的反应.
- 描述由OTA形成的DNA添加物及其对毒性的影响.
主要方法:
- 电子喷射质谱和NMR光谱被用来分析反应产物.
- 在dG的存在下使用光刺激和氧化激活 (HRP/H2O2,Fe(II,Cu(II)) 的OTA.
主要成果:
- 成功地分离和识别了C8-脱氧氨酸核酸添加物 (添加物4) .
- 通过光刺激和OTA的氧化激活,形成了相同的 adduct.
- 这一补充证实了OTA与dG结合的能力.
结论:
- OTA可以直接与脱氧氨酸反应,形成C8-dG附加物,为其致变性提供了分子基础.
- 这项研究描述了基毒素的第一个核酸添加物,为OTA和相关化合物的作用机制提供了洞察力.
- 这些发现对理解性异种生物制剂的基因毒性有重大意义.
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