2,9-双甲基苯并噻唑乙烯基邻菲咯啉与DNA的相互作用及应用研究

Interaction of a Phenanthroline Derivative with DNA and Its Application

设计合成了基于2,9-双苯并噻唑乙烯基取代的邻菲咯啉荧光分子PMBT。通过吸收光谱、荧光光谱、圆二色谱探讨了PMBT与不同DNA的相互作用,发现PMBT与DNA存在两种不同的相互作用模式。由于PMBT分子中带有2个正电荷,当PMBT与DNA的浓度比值较高(大于4)时,PMBT以DNA为模板按一定方向在DNA上聚集;当PMBT与DNA的浓度比小于2时,PMBT通过嵌插或末端堆积的方式分别与单/双链DNA和G-四链体DNA结合。PMBT与DNA结合导致其荧光猝灭,利用该特性将PMBT与DNA结合构建荧光增强型检测平台,可用于DNA酶活性以及DNA降解的动力学研究。

A phenanthroline derivative,2,9-bis{ 2-（ 3-methylbenzo[d]thiazol-2-yl） vinyl}-1,10-phenanthroline（ PMBT）,was designed and synthesized. The interaction of PMBT with different DNA forms was investigated by UV-Vis absorption spectrum,fluorescence spectrum and circular dichroism spectrum. PMBT possesses a large conjugated planar structure,and binds to DNA with different modes dependent on the molecular ratio of PMBT and DNA. At high molecular ratio（ 4）,PMBT binds to DNA through DNA-templated aggregation because of the two positive charges on each of PMBT. At low molecular ratio（ 2）,PMBT binds to DNA through intercalation between the DNA bases or end-stacking on G-quadruplexes. PMBT has good solubility in aqueous solution,and exhibits strong fluorescence. The fluorescence is quenched when bound to DNA. Thus PMBT was used as a fluorescent probe for investigation of DNA degradation in serum and the activity of nuclease.