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DNA单链(PS2.M)在K~+存在下可被诱导形成G-四链体。文章利用圆二色谱(CD)以及核磁共振光谱(NMR)表征了G-四链体的形成,并通过荧光滴定光谱、紫外滴定光谱以及核磁共振光谱研究了盐酸药根碱与G-四链体的相互作用。加入G-四链体后,药根碱在530nm处的荧光明显增强;紫外吸收光谱表现出减色和红移现象,说明药根碱可能堆积到G-四链体的尾部或者插入到G-四链体尾部的两个G-四分体之间形成夹心结构。由等摩尔连续变化法算出药根碱和DNA的结合比为1∶1,利用Scatchard方程计算出二者的结合常数为3.12×10~6 L/mol、结合位点为0.98。实验表明:盐酸药根碱与G-四链体有很强的相互作用,药根碱可以稳定DNA的G-四链体结构,二者的作用模式可能为末端堆积。
DNA single strand (PS2.M) can be induced to form a G-quadruplex in the presence of K ~ +. The formation of G-quadruplex was characterized by circular dichroism (CD) and nuclear magnetic resonance spectroscopy (NMR). The effects of jatrorrhizine hydrochloride and G-quadruplex were studied by fluorescence titration, UV-vis and nuclear magnetic resonance Interaction. After addition of G-quadruplex, the fluorescence of jatrorrhizine at 530 nm was significantly enhanced. The UV-absorption spectrum showed reduction and red-shift phenomenon, indicating that jatrorrhizine could accumulate to the tail of G-quadruplex or inserted into G- The tetragonal structure forms between the two G-quarters of the tail of the quadruplex. The conjugation ratio of jatrorrhizine and DNA was calculated to be 1: 1 by equimolar continuous change method. The binding constant was 3.12 × 10 ~ 6 L / mol and the binding site was 0.98 using the Scatchard equation. The experimental results show that the jatrorrhizine hydrochloride has a strong interaction with the G-quadruplex, and the jatrorrhizine can stabilize the G-quadruplex structure of the DNA. The mode of action of the jatrorrhizine may be terminal packing.