Simultaneous and site-directed incorporation of an ester linkage and an azide group into a polypeptide by in vitro translation
作者:Martin Humenik、Yiwei Huang、Igor Safronov、Mathias Sprinzl
DOI:10.1039/b909188b
日期:——
A method is presented by which an azide-containing side chain can be introduced into any internal position of a polypeptide chain by in vitro translation. For this, 2′-deoxy-cytidylyl-(3′→5′)-adenosine was acylated on the 3′(2′)-hydroxyl group of adenosine with 6-azido-2(S)-hydroxyhexanoic acid (AHHA), an α-hydroxy- and ε-azide derivative of L-lysine. The acylated dinucleotide was enzymatically ligated with a tRNA transcript to provide chemically stable E. coli suppressor AHHA-tRNACys(CUA). The esterase 2 gene from Alicyclobacillus acidocaldarius was modified by the amber stop codon (UAG) on position 118. Using AHHA-tRNACys(CUA) in an E. coli in vitro translation/transcription system, the site-directed introduction of an azide group linked to a backbone ester into the esterase polypeptide was achieved. The yield of the synthesized modified protein reached 80% compared to translation of the native esterase. Subsequently, azide coupling with an alkyne-modified oligodeoxynucleotide demonstrated the feasibility of this approach for conjugation of polypeptides.
本文介绍了一种方法,通过体外翻译技术,将含有叠氮的侧链引入多肽链的任意内部位置。为此,利用6-叠氮-2(S)-羟基己酸(AHHA)——L-赖氨酸的α-羟基和ε-叠氮衍生物,对2′-脱氧胞苷酰-(3′→5′)-腺苷酸的腺苷3′(2′)-羟基进行酰化。通过酶促连接反应,将酰化的二核苷酸与tRNA转录本结合,形成化学稳定的AHHA-tRNACys(CUA)大肠杆菌抑制子。对Alicyclobacillus acidocaldarius酯酶2基因的第118位进行修改,引入终止密码子UAG。在E. coli体外翻译/转录系统中使用AHHA-tRNACys(CUA),实现了在酯酶多肽链中引入连接到骨架酯的叠氮基团。与天然酯酶的翻译相比,合成修饰蛋白的产量达到了80%。此后,叠氮与烷炔修饰的寡脱氧核苷酸的耦合实验证明了这种方法在多肽耦合中的可行性。