Department of Biochemistry, University of Utah School of Medicine, 15 North Medical Drive East, Room 4100, Salt Lake City, Utah 84112-5650, USA.
Department of Pediatrics, Division of Diabetes and Endocrinology, Stanford University, Palo Alto, CA 94304, USA.
Org Biomol Chem. 2021 Oct 20;19(40):8821-8829. doi: 10.1039/d1ob01611c.
Native chemical ligation (NCL) enables the total chemical synthesis of proteins. However, poor peptide segment solubility remains a frequently encountered challenge. Here we introduce a traceless linker that can be temporarily attached to Glu side chains to overcome this problem. This strategy employs a new tool, Fmoc-Glu(AlHx)-OH, which can be directly installed using standard Fmoc-based solid-phase peptide synthesis. The incorporated residue, Glu(AlHx), is stable to a wide range of chemical protein synthesis conditions and is removed through palladium-catalyzed transfer under aqueous conditions. General handling characteristics, such as efficient incorporation, stability and rapid removal were demonstrated through a model peptide modified with Glu(AlHx) and a Lys solubilizing tag. Glu(AlHx) was incorporated into a highly insoluble peptide segment during the total synthesis of the bacteriocin AS-48. This challenging peptide was successfully synthesized and folded, and it has comparable antimicrobial activity to the native AS-48. We anticipate widespread use of this easy-to-use, robust linker for the preparation of challenging synthetic peptides and proteins.
天然化学连接（NCL）能够实现蛋白质的全化学合成。然而，肽段溶解性差仍然是一个常见的问题。在这里，我们引入了一种无痕迹连接子，可以暂时连接到 Glu 侧链以克服这个问题。该策略使用了一种新的工具，Fmoc-Glu(AlHx)-OH，它可以使用标准的 Fmoc 固相肽合成直接安装。所结合的残基 Glu(AlHx)在广泛的化学蛋白质合成条件下稳定，并通过钯催化在水性条件下转移去除。通过用 Glu(AlHx)和 Lys 溶解标签修饰的模型肽，证明了其具有高效掺入、稳定性和快速去除等一般处理特性。Glu(AlHx)被掺入到细菌素 AS-48 的全合成中的一个高度不溶性肽段中。这个具有挑战性的肽成功地被合成和折叠，并且具有与天然 AS-48 相当的抗菌活性。我们预计这种易于使用、稳健的连接子将广泛用于制备具有挑战性的合成肽和蛋白质。
