【作者】 李洪晶；

【导师】 李正强；

【作者基本信息】 吉林大学 ， 生物化学与分子生物学， 2008， 硕士

【摘要】 自1979年Fiel等人证实水溶性四-(4-甲基吡啶基)卟啉-TMPyP能嵌入DNA的碱基以来,TMPyP与各种DNA以及其他生物大分子相互作用的研究一直倍受关注。然而对TMPyP在各种外界环境条件下其结构特性的研究近几年刚刚起步,但这种研究对理解重要的生命过程和生物模拟具有重要意义。本文利用紫外可见光谱,荧光光谱,圆二色谱,拉曼光谱研究了四氢呋喃和水组成的混合溶剂中TMPyP自身结构变化及加入酸碱盐后的结构变化;改变TMPyP与ctDNA的摩尔比(R=[DNA]/[TMPyP])对二者作用模式的影响;TMPyP与DNA相互作用的作用模式受盐离子浓度变化的影响。主要实验结果如下:1. TMPyP在溶剂诱导下大环平面性增强,侧链正电荷与大环π键之间形成共轭;2.在HCl诱导下发生质子化并得到J-聚集体;3.在NaOH诱导下得到J-聚集体,此聚集体与HCl诱导生成的J-聚集体不同;4.改变TMPyP浓度不影响其与ctDNA作用的插入模式,改变R值却对作用模式影响很大;5.溶液中的盐离子浓度对TMPyP与ctDNA相互作用的作用模式的影响较小。上述结果,为我们今后进一步研究TMPyP与核酸相互作用的机制提供了基础。更多还原

【Abstract】 Porphyrins is a general term of the homologue and derivative of porphine with substituting groups at the outside ring, becoming metalloporphyrins promptly after two protons on its nitrogen are replaced by the metal ion. This is one kind widely exists in the plants and animals, has the special activity. The heme, the chlorophyll is its typical representative. As early as in 1930s, porphyrins have been under intensive study. And now they have been widely used in many fields of biochemistry, medicine, analytical chemistry, bionics . TMPyP is one of porphyrins that many people pay attention to it in early.Since 1979, Feil and co-workers reproted that TMPyP and its metal derivatives can intercalate into DNA, the interaction of TMPyP with a variety of DNA, RNA and other biological macromolecules has been paid much attention. And that have a good application prospect in Biological Sciences. The nature of TMPyP has been studied in detail from recent years, and there is much significance for Life Processes Understanding.By using UV-visible spectroscopy, Fluorescence Spectroscopy, Circular Dichroism, Raman spectroscopy , we studied the ionic strength and solvent effect on the structure of TMPyP, the binding mode of TMPyP and ctDNA , the mode change by the salt ions.The structure of TMPyP changes with solvent-induced, the organic component - water mixtures from tetrahydrofuran and water, divided into four gradient inspection, the total volume of tetrahydrofuran followed by the ratio of 0%, 2.5%, 50%, 90% . Found TMPyP porphyrin would have occurred nuclear distorted , side positive charge and macrocyclicπbond formed between conjugate in the solvent-induced. The structure changes after adding acid alkali and salt,divided into three concentration gradient,0,20 mM, 100mM. Found little effect on the porphyrin after adding NaCl, Be protonated and obtained J-aggregates after adding a proton of HCl , obtained aggregates after adding NaOH ,two aggregates have different the formation mechanism.Interaction of TMPyP and ctDNA , change the molar ratio (R = [DNA] / [TMPyP]),Found the concentration of DNA not TMPyP can affect the binding mode largely. Intercalation model changes little after injecting salt ions.The above research is very important for the study of TMPyP’nature and the development for supermolecular structure,but also for the detailed study of the interaction TMPyP with DNA and other biological macromolecules .更多还原