关于咖啡因与核酸的相互作用。IV. 利用红外和紫外线性二色性、质子和氘核核磁共振研究咖啡因与DNA的相互作用

On the interaction of caffeine with nucleic acids. IV. Studies of the caffeine-DNA interaction by infrared and ultraviolet linear dichroism, proton and deuteron nuclear magnetic resonance.

作者信息

Fritzsche H, Lang H, Sprinz H, Pohle W

出版信息

Biophys Chem. 1980 Feb;11(1):121-31. doi: 10.1016/0301-4622(80)85014-9.

Abstract

The DNA-caffeine interaction at high concentration of caffeine (Cf) leads to an arrangement of Cf molecules outside of the DNA double helix with an orientation parallel to the bases both in the A and B form as demonstrated by infrared linear dichroism. Addition of DNA broadens the 1H NMR lines of Cf in aqueous solution indicating a specific binding. Intercalation is not the predominant mechanism, the deuterium relaxation time T1 = (38 +/- 7) ms and the estimated reorientation correlation time tau cb = 0.17 ns of caffeine-8[2H] in the Cf-DNA complex suggest an outside stacking of the ligand. According to the results a model on the DNA-Cf complex at high Cf concentration (binding process II) is suggested including the caffeine-induced reorientation of the hydration shell of DNA.

摘要

高浓度咖啡因（Cf）与DNA的相互作用导致Cf分子排列在DNA双螺旋外部，其取向与A和B型中的碱基平行，这由红外线性二色性证明。DNA的加入拓宽了Cf在水溶液中的1H NMR谱线，表明存在特异性结合。嵌入不是主要机制，Cf-DNA复合物中咖啡因-8[2H]的氘弛豫时间T1 =（38±7）ms，估计的重取向相关时间τcb = 0.17 ns，表明配体在外部堆积。根据这些结果，提出了一个高Cf浓度下DNA-Cf复合物的模型（结合过程II），其中包括咖啡因诱导的DNA水合壳重取向。