以修飾光解輔助基團之天門冬醯胺進行天然化學連接法

Photocleavable Auxiliary at Asn for Native Chemical Ligation

張浙杰(Zhe-jie Zhang)

指導教授 ： 林俊成

國立清華大學/理學院/化學系所/碩士(2017年)

摘要

天然化學連接法（Native chemical ligation，NCL）是高效實用的主流多肽/蛋白質化學合成方法，彌補了固相多肽合成法在合成多肽鏈長度上的局限。但天然化學連接法依賴半胱氨酸（Cysteine）以進行多肽鏈間的連接，而半胱氨酸在天然蛋白質中含量極少（約1%），極大地限制了NCL 的運用。
本實驗室先前開發出一種光解輔助基以修飾天門冬氨酸，並成功將其引入寡肽之間的天然化學連接。本研究目標是將類似光解基團修飾在天門冬醯胺上，使其成為可直接應用於固相多肽合成（Solidphase-peptide-synthesis, SPPS）的氨基酸組件。使用被修飾的天門冬醯胺代替半胱氨酸在水相緩衝溶液中進行天然化學連接。完成連接後施加紫外線光照，在溫和的反應條件下除去完成使命的輔助基團，得到“天然”的目標多肽。

關鍵字

天然化學連接法 ； 天門冬醯胺 ； 光解輔助基團

並列摘要

Native chemical ligation(NCL) is a practical and efficient methodology for peptide/proteins synthesis. However, the rare presence of the cysteine residue (1.4% content in proteins) has limited the utility of NCL (most peptide pharmaceuticals rarely contain an internal cysteine).
The previously work in our lab already developed a photocleavable auxiliary to modify Asp. Such building block has been used in NCL between dipeptides. The method of this job relied on Photocleavable-auxiliary-modified Asn/Gln to achieve NCL. Modified Asn/Gln can take place the role of Cys in NCL. Using solid-phase peptide synthesis (SPPS) to synthesis peptide sequences, then ligate peptide sequences by NCL. We use UV irradiation after NCL to obtain target peptide mild and rapidly.
The objective of this job is use such method to achieve NCL between
short-sequence peptides ligation and produce a valuable peptide/protein.

並列關鍵字

Native Chemical Ligation ； Asn ； Photocleavable Auxiliary

參考文獻

1. Merrifield, R. B., Solid phase peptide synthesis. I. The synthesis of a tetrapeptide.

J. Am. Chem. Soc. 1963, 85, 2149-2154.

2. Dawson, P. E., Muir, T. W.; Clark-Lewis, I.; Kent, S. B., Synthesis of proteins by native chemical ligation. Science 1994, 226, 776-779.

4. Sheehan, C. J., Cruickshank, P. A., Boshart, G. L., A convenient synthesis of water- soluble carbodiimides. J. Org. Chem. 1961, 26, 2525-2528.

5. König, W.; Geiger, R., Eine neue Methode zur Synthese von Peptiden: Aktivierung der Carboxylgruppe mit Dicyclohexylcarbodiimid unter Zusatz von 1-Hydroxy-benzotriazolen. Chem. Ber. 1970, 103, 788–798.