以界面活性分子分離去氧核醣核酸結構之研究

Development of Surfactant Molecule for DNA Structural Separation

侯冠宇(Kuan-Yu Hou)

指導教授 ： 張大釗

國立臺灣大學/理學院/化學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.02181

摘要

3,6-雙(4-甲基化吡啶烯基)咔唑 (BMVC) 是一個有機螢光分子，實驗發現它不僅和DNA結合後會產生大幅的螢光增強，並且對於不同結構的DNA具有不同的結合趨勢。利用此對DNA結構上的選擇性，可以將BMVC應用在不同結構DNA的分離上。
本篇主旨是在BMVC的九號氮位置上接上長碳鏈，將分子改造成具有親水端及親脂端的界面活性分子BMVC-22C，當此分子處在DNA混合溶液及有機溶劑中時，便會整齊地排列在兩溶液的界面之間，藉由分子中BMVC端對不同DNA結構間的選擇性，可以將特定的DNA結構以逆微胞的方式從水層中帶到有機層，讓我們利用類似萃取的方式將不同結構DNA分離。
實驗結果顯示利用此BMVC衍生物及萃取的方式，能夠讓我們將雙股、平行四股與非平行四股的DNA結構進行分離，配合CD和NMR光譜的結果，有效地簡化DNA結構分析的複雜度，並且能夠將特定的DNA結構單獨分離出來。此成果除了在DNA研究上具有重要意義外，同時將BMVC分子的價值擴展到更廣泛的應用範疇。

關鍵字

DNA四股結構 ； 分離 ； 萃取 ； 界面活性分子 ； 逆微胞

並列摘要

A new method is developed for DNA structural separation. This method has adopted the special characteristics of a small fluorescent molecule, called 3,6-Bis(1-methyl-4-vinylpyridinium) carbazole (BMVC). As an effective G-quadruplex stabilizer, BMVC has different binding affinities to different DNA conformations such as parallel or anti-parallel DNA quadruplex. Based on this distinctive property of BMVC, we synthesized a new derivative of BMVC for DNA structural separation.
The novel method based on surfactant extraction is introduced for DNA structural separation. We synthesized a lipophilic derivative of BMVC, 3,6-Bis(1-methyl-4-vinylpyridinium)-9-docosanyl carbazole (BMVC-22C), which can act as a surfactant molecule. It can stably align at the interface between two immiscible solutions such as water and dichloromethane. With its unique binding property, the BMVC-22C molecule shows an ability to selectively capturing certain specific DNA structures. It is similar to the solvent extraction for separating the bound and free DNAs, i.e., the bound DNA will be captured into the lower solution via inverse micelle formed by surfactant molecule BMVC-22C, while the free DNA can be collected at the upper solution. The surfactant extraction method is able to isolate the parallel G-quadruplexes from non-parallel G-quadruplexes or linear duplexes. Using this method, one can isolate the conformations with different binding preferences to BMVC-22C individually. However, the efficiency for separating parallel G-quadruplexes and non-parallel G-quadruplexes is not good enough which can only be done at low temperature. We thus introduce previously developed emulsion induced filtration (EIF) to solve this problem. With the combination of these two methods, we can separate parallel G-quadruplexes and non-parallel G-quadruplexes in a more effective way.
In conclusion, the method of surfactant extraction is established by combining extraction with molecular design, which can separate different DNA structures and obtain each conformation successfully. The results play important roles in both scientific research and biochemical fields.

並列關鍵字

DNA quadruplex ； separation ； extraction ； surfactant molecule ； inverse micelle

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