Open AccessA Glutamic Acid-based Traceless Linker to Address Challenging Chemical Protein Syntheses
Author(s) -
Riley J Giesler,
Paul Spaltenstein,
Michael T. Jacobsen,
Weiliang Xu,
Mercedes Maqueda,
Michael S. Kay
Publication year - 2021
Publication title -
organic and biomolecular chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 146
eISSN - 1477-0539
pISSN - 1477-0520
DOI - 10.1039/d1ob01611c
Subject(s) - chemistry , linker , peptide , native chemical ligation , combinatorial chemistry , peptide synthesis , residue (chemistry) , chemical synthesis , solid phase synthesis , solubility , side chain , amino acid , chemical ligation , chemical stability , organic chemistry , biochemistry , in vitro , polymer , computer science , operating system
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 6 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.