Synthesis and use of a pseudo-cysteine for native chemical ligation

J Pept Sci. 2003 Apr;9(4):221-8. doi: 10.1002/psc.448.

Abstract

The process of native chemical ligation (NCL) is well described in the literature. An N-terminal cysteine-containing peptide reacts with a C-terminal thioester-containing peptide to yield a native amide bond after transesterification and acyl transfer. An N-terminal cysteine is required as both the N-terminal amino function and the sidechain thiol participate in the ligation reaction. In certain circumstances it is desirable, or even imperative, that the N-terminal region of a peptidic reaction partner remain unmodified, for Instance for the retention of biological activity after ligation. This work discusses the synthesis of a pseudo-N-terminal cysteine building block for incorporation into peptides using standard methods of solid phase synthesis. Upon deprotection, this building block affords a de facto N-terminal cysteine positioned on an amino acid sidechain. which is capable of undergoing native chemical ligation with a thioester. The syntheses of several peptides and structures containing this motif are detailed, their reactions discussed. and further applications of this technology proposed.

MeSH terms

  • Amino Acid Sequence
  • Cysteine / analogs & derivatives*
  • Cysteine / chemical synthesis
  • Green Fluorescent Proteins
  • Luminescent Proteins / chemistry
  • Peptides / chemical synthesis*

Substances

  • Luminescent Proteins
  • Peptides
  • Green Fluorescent Proteins
  • Cysteine