色胺修饰竹红菌素及其稀土离子配位聚合物与DNA相互作用研究  

Studies on the Interaction of DNA with Tryptamine Modified Hypocrellin and its Rare Earth Metal Coordination Polymers

作　　者：欧植泽[1] 陈晨[1] 高云燕[1] 曹璐[1] 刘桂霞[1] 李慧珍[1] 

机构地区：[1]西北工业大学理学院 空间应用物理与化学教育部重点实验室,陕西西安710072

出　　处：《影像科学与光化学》2013年第5期361-374,共14页Imaging Science and Photochemistry

摘　　要：利用紫外-可见吸收光谱、荧光光谱、圆二色谱(CD)等方法研究了色胺修饰竹红菌素(DTrpHA)及其稀土离子配位聚合物(Y3+-DTrpHA,La3+-DTrpHA)与小牛胸腺DNA(CT DNA)和G-四链体22AG的相互作用.结果表明,DTrpHA及其配位聚合物中的色胺基团和竹红菌素基团均参与和双链CT DNA的作用,作用方式主要为沟槽作用.与G-四链体DNA作用后,DTrpHA及其配位聚合物中的色胺基团均具有较大的减色效应(>45%)和峰位红移(≥4nm),说明色胺基团与G-四链体采用外部堆积作用方式结合;而竹红菌素基团的减色效应相对较小且无明显峰位变化,表明竹红菌素基团采用非特异性作用方式与G-四链体的环区碱基或糖-磷酸骨架结合.G-四链体22AG的构象主要为分子内反平行结构,加入DTrpHA及其配位聚合物对G-四链体22AG的构象影响较小.Y3+-DTrpHA比DTrpHA和La3+-DTrpHA与G-四链体具有更强的相互作用.Y3+-DTrpHA使得CT DNA的熔解温度(Tm)上升了仅1.9℃,而使G-四链体的熔解温度上升了13.1℃.荧光嵌插剂置换实验(FID)结果表明,Y3+-DTrpHA对G-四链体具有良好亲和性,具有较小的G4 DC50值(使噻唑橙/G-四链体体系荧光下降50%所需配体或配合物的浓度)和较高的G-四链体选择性.Interaction of tryptamine modified hypocrellin （DTrpHA） and its coordination polymers （Y3＋-DTrpHA,La3＋-DTrpHA） with DNA,including calf thymus DNA （CT DNA）and G-quadruplex 22AG,is studied by UV-Vis absorption spectroscopy,fluorescence spectroscopy and circular dichroism （CD） spectroscopy.The results indicate that the groove binding are the major mode for the association of CT DNA with DTrpHA and its coordinaiton polymer.Large hypochromicity （＞ 45％） and red-shift in the absorption peak of tryptamine group （≥4 nm） in DTrpHA and its coordination polymers are observed,suggesting an external end-stacking mode involved.However,less hypochromicity and no obvious red-shift in the absorption peak of hypocrellin moiety in DTrpHA and its coordination polymers,suggesting that the binding mode of hypocrellin moiety could involve non-specific interactions to loop bases or sugar-phosphate backbone of G-quadruplex.G-quadruplex 22AG maintains intramolecular antiparallel structure before and after association with DTrpHA or its coordination polymers.y3＋-DTrpHA has stonger interaction towards G-quadruplex structure than DTrpHA and La3＋-DTrpHA.Y3＋-DTrpHA can slightly increase the melting temperature （Tm） of CT DNA by only 1.9 ℃,but increase the Tm of G-quadraplex by 13.1 ℃.Fluorescent intercalator displacement （FID） assay results demonstrate that Y3＋-DTrpHA possesses high affinity towards G-quadruplex with low G4DC50 value （the required concentration of ligand or complex that the fluorescence reduced 50％ in TO/G-quadruplex system） and displays good selectivity for G-quadruplex over duplex DNA.

关 键 词：配位聚合物 G-四链体 竹红菌素 抗癌药物 

分 类 号：O634[理学—高分子化学] R914[理学—化学]