Fmoc-based synthesis of peptide α-thioesters using an aryl hydrazine support
Fmoc-based synthesis of peptide α-thioesters using an aryl hydrazine support
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DOI：
10.1021/jo040140h
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发表时间：
2004-06-11
影响因子：
3.6
通讯作者：
Mitchell, AR
中科院分区：
文献类型：
--
作者：
Camarero, JA;Hackel, BJ;Mitchell, AR
C末端肽硫酯是通过天然化学连接合成/半合成蛋白质和环肽的关键中间体。它们通过固相肽合成（SPPS）或通过蛋白质剪接技术生物合成来制备。直到最近，由于硫酯键对N-α-Fmoc基团脱保护所需的碱性条件的稳定性差，通过SPPS的C-末端α-硫酯肽的化学合成在很大程度上限于使用Boc/苄基化学。在目前的工作中，我们描述了一种新的方法，为C-端硫酯的SPPS使用Fmoc/t-Bu化学。该方法基于使用芳基肼连接体，其对Fmoc-SPPS所需的条件完全稳定。当肽合成完成时，通过温和氧化实现接头的活化。该步骤将酰基肼基团转化为高反应性酰基二氮烯中间体，其与α-氨基酸烷基硫酯（H-AA-SR）反应，以良好的产率产生相应的肽α-硫酯。这种方法已成功地用于制备各种肽硫酯，环肽，和一个全功能的Src同源3（SH 3）蛋白结构域。
C-Terminal peptide thioesters are key intermediates in the synthesis/semisynthesis of proteins and of cyclic peptides by native chemical ligation. They are prepared by solid-phase peptide synthesis (SPPS) or biosynthetically by protein splicing techniques. Until recently, the chemical synthesis of C-terminal a-thioester peptides by SPPS was largely restricted to the use of Boc/Benzyl chemistry due to the poor stability of the thioester bond to the basic conditions required for the deprotection of the N-alpha-Fmoc group. In the present work, we describe a new method for the SPPS of C-terminal thioesters using Fmoc/t-Bu chemistry. This method is based on the use of an aryl hydrazine linker, which is totally stable to conditions required for Fmoc-SPPS. When the peptide synthesis has been completed, activation of the linker is achieved by mild oxidation. This step converts the acyl hydrazine group into a highly reactive acyl diazene intermediate which reacts with an a-amino acid alkyl thioester (H-AA-SR) to yield the corresponding peptide a-thioester in good yield. This method has been successfully used to prepare a variety of peptide thioesters, cyclic peptides, and a fully functional Src homology 3 (SH3) protein domain.