Abstract

The present study sought to evaluate the interaction between aflatoxin G₁ and free DNA in vitro through different analytical techniques. The UV–visible spectra results showed that the structure of DNA might be changed with a new aflatoxin G₁-DNA complex forming, which indicated that the interacting mode between them was the intercalating mode. The DNA melting temperature increased by 12.80 °C, suggesting that the DNA double helix structure was more compact and stable through intercalation. The circular dichroism (CD) spectra results indicated that the interaction of aflatoxin G₁ with DNA induced the DNA base stacking changes. The results of agarose gel electrophoresis and fluorescence microscope further verified that the interacting mode between aflatoxin G₁ and DNA was intercalation mode. According to the fluorescence spectrum data, the binding constant was calculated 6.24 × 10⁴ L·mol⁻¹. The thermodynamic results demonstrated that the reaction of aflatoxin G₁ intercalating to DNA was a spontaneous reaction. The elimination results suggested that aflatoxin G₁ could be enriched and removed by DNA intercalation through magnetic beads separation, with the removal efficiency of 93.73%. The study results would provide a theoretical basis for establishing a new aflatoxin removal method based on DNA intercalation.

摘要

本研究试图通过不同的分析技术在体外评估黄曲霉毒素 G ₁与游离 DNA之间的相互作用。紫外-可见光谱结果表明DNA的结构可能随着新的黄曲霉毒素G ₁ -DNA复合物的形成而改变，表明它们之间的相互作用模式为嵌入模式。DNA 解链温度升高了 12.80 °C，表明 DNA 双螺旋结构通过嵌入更加紧密和稳定。圆二色性 (CD) 光谱结果表明黄曲霉毒素 G ₁用 DNA 诱导 DNA 碱基堆积变化。琼脂糖凝胶电泳和荧光显微镜结果进一步验证了黄曲霉毒素G ₁与DNA的相互作用模式为嵌入模式。根据荧光光谱数据，结合常数计算为6.24 × 10 ⁴ L·mol ^-1。热力学结果表明，黄曲霉毒素G ₁嵌入DNA 的反应是自发反应。消除结果表明黄曲霉毒素 G ₁可通过磁珠分离通过DNA嵌入富集去除，去除效率达93.73%。该研究结果将为建立一种基于DNA嵌入的黄曲霉毒素去除新方法提供理论依据。