中文摘要：

在生理酸度条件下（pH 7.4）,运用紫外-可见吸收光谱法、荧光光谱法、圆二色光谱法（CD）和红外光谱法（FT-IR）并结合粘度实验和熔点测量,研究了麦芽酚（MAL）与小牛胸腺DNA（ctDNA）之间的结合性质和结合模式。实验结果表明,MAL与ctDNA的结合未引起ctDNA的熔点和粘度产生明显变化,NaCl浓度的增加,对MAL-ctDNA体系紫外吸光度无明显影响,表明二者是以沟槽方式结合且不存在静电作用。计算出的热力学参数表明,MAL与ctDNA的结合作用主要由氢键和范德华力驱动。圆二色谱和红外光谱分析表明,MAL更倾向于与ctDNA的T碱基结合,并诱导ctDNA由从正常的B型结构转变为高度松散的B型ctDNA结构。分子模拟直观展示了MAL与ctDNA的结合模式为沟槽结合,且主要结合在ctDNA的T碱基富集区,证实了实验结果。凝胶电泳实验表明,MAL没有引起DNA明显损伤。

英文摘要：

The binding properties and mode associated with calf thymus DNA（ctDNA）upon interaction with maltol（MAL）in vitro were investigated in physiological buffer（pH 7.4）by ultraviolet-visible absorption（UV-vis）,fluorescence,circular dichroism（CD）and fourier transform infrared spectroscopy（FTIR）coupled with melting experiments and viscosity measurement.The results showed that the relative viscosity and melting temperature of DNA did not changed significantly,and the UV-vis absorbance had no obvious change with increasing concentration of NaCl,which indicated that the mode between MAL and ctDNA was groove and no electrostatic.The calculated thermodynamics parameters by the temperature experiment of ultraviolet showed that hydrogen bonding and van der Waals force were main force.Results from CD and FT-IR analysis manifested that the specific binding site was T base,and MAL induced B-form of ctDNA varied from normal morphology to loose morphology.Then the molecular docking further verified the results of experiments and intuitively showed the binding pose of MAL with ctDNA.The results of agarose gel electrophoresis indicated that MAL didn＇t induce DNA damage.