DNA‐biding of IQ, Me‐IQ and Me‐IQx, strong mutagens found in broiled foods

FEBS Letters

Watanabe, Tatsuo³  Miyazawa, Tatsuo¹  Yokoyama, Shigeyuki³  Kasai, Hiroshi²  Hayashi, Kenshi²  Nishimura, Susumu² 

[1] Biochemistry Division and Chuo-ku, Tokyo 104, Japan;Biology Division, National Cancer Center Research Institute, Chuo-ku, Tokyo 104, Japan;Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan

关键词: Mutagen;    Carcinogen;    Broiled food;    DNA-binding;    Intercalation;    Binding constant;   

DOI  :  10.1016/0014-5793(82)80784-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Non-covalent DNA-binding has been studied of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (Me-IQ) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (Me-IQx), strong mutagens found in broiled foods. These mutagens are intercalated into DNA, as found by ultraviolet absorption gel electrophoresis. The binding of IQ is stronger with GC pairs than AT pairs in DNA. The binding constants with calf thymus DNA are 1.6 × 10⁶ (Me-IQ), 0.9 × 10⁶ (IQ) and 0.7 × 10⁶ M⁻¹ (Me-IQx) at pH 6.0. This order of DNA affinity agrees with the order of mutagenicity towards Salmonella typhimurium TA98.

【 授权许可】

Unknown