A-T Rich DNA與新型胜肽的鍵結研究

The Binding Studies of A-T Rich DNA and a Novel Peptide

張書銘

指導教授 ： 程家維

國立清華大學/生命科學院/生物科技研究所/碩士(2010年)

摘要

DNA是生物體中重要的遺傳物質。其所攜帶的基因訊息，透過複製、轉錄，影響了細胞內重要的生化反應。許多特定的蛋白質會選擇性地作用到特定的DNA片段以調控這些反應。而許多小分子藥物因此被設計出來作用到DNA序列上，干擾蛋白質與DNA的作用，以達到抑制癌症與相關疾病的目的。在本次研究中，我們以XPRK motif與pyrrole設計出新型胜肽，序列為Gln-Hyp-Arg-Lys-(Py)4-Arg-Lys-NH2 (HyQ-10)，並以d(AGGAGAAAATAC)2雙股螺旋DNA當做我們的目標片段。藉由NMR二維光譜，我們解析出d(AGGAGAAAATAC)2的序列資訊。在HyQ10的滴定實驗中，我們發現隨著滴定比例的增加，靠近A/T連續位置的影響越強，其中又以T連續的位置鍵結最穩定。而在滴定過程中，我們只發現一組新的交叉峰型式，顯示HyQ-10與DNA可能只有一種結合模式。

關鍵字

核磁共振 ； 胜肽

並列摘要

DNA is an important molecule in the organism. The genetic information carried by DNA regulates important biochemical reactions by replication and transcription. Many proteins selectively bind to DNA fragment to regulate these reactions. Therefore, many small molecules were designed to recognize these specific DNA sequences to block the interaction between proteins and DNA and to inhibit cancer and other disease. In this study, we designed a novel peptide contains the XPRK motif and Py residue. The sequence of the designed peptide is Gln-Hyp-Arg-Lys-(Py)4-Lys-Arg-NH2 (HyQ-10). We chose a duplex d(AGGAGAAAATAC)2 as our target. By 2D NMR spectroscopy, we got the sequential assignment of d(AGGAGAAAATAC)2. In the HyQ-10 titraion experiment, we find out that the residues around the A/T-rich site will get the larger influence. And the consecutive T site has the most stable binding. In the titration experiment, we only found out a new cross peak mode, indicating that HyQ-10 and d(AGGAGAAAATAC)2 may have only one binding mode.

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