【摘要】 本文应用吸收光谱分析法研究了交链孢酚(AOH)与人胚食管DNA的结合作用。结果表明,两者在37℃条件下反应迅速而稳定,显示吸收程度下降和最大吸收峰向长波方向明显位移,且幅度随另一方的浓度增大而增大,有明显的剂量依赖性。结合部位可能在碱基,但无明显的碱基特异性,结合的最大分子比例(以AOH:脱氧磷酸核苷计)为5:1000;反应的平衡常数K=3.4×10~6。DNA热变性后结合增强,盐离子可严重干扰,而脲无明显影响,提示AOH与DNA主要以离子键结合,这种结合方式可能在ADH的诱变/致癌活性中起重要作用。更多还原

【Abstract】 In this paper, the binding reaction between alternariol (AOH) and the human fetal esophagus DNA was studied with spectrophotometric method. It was found that the reaction occured quickly and stably at 37 C, showing decrease and shift toward longer wave length of absorbance dosedependently. The site of binding may be on bases in 5 AOH molecules/1000 nucleotides. The association constant (K) was 3.4 × 106. It was also showed that the reaction was increased with heat denatured DNA, decreased by salt and unaffected by urea. These results gave the suggestion that the binding between AOH and human fetal esonhaguspDNA was most likely by ionic bond and this kind of binding maybe play an important rote in mutagenicity and carcinogenicity of AOH.更多还原