Section 59
Chapter 58,775

Ribosomal Synthesis of Macrocyclic Peptides in Vitro and in Vivo Mediated by Genetically Encoded Aminothiol Unnatural Amino Acids

Frost, J.R.; Jacob, N.T.; Papa, L.J.; Owens, A.E.; Fasan, R.

Acs Chemical Biology 10(8): 1805-1816


ISSN/ISBN: 1554-8929
PMID: 25933125
DOI: 10.1021/acschembio.5b00119
Accession: 058774052

A versatile method for orchestrating the formation of side chain-to-tail cyclic peptides from ribosomally derived polypeptide precursors is reported. Upon ribosomal incorporation into intein-containing precursor proteins, designer unnatural amino acids bearing side chain 1,3- or 1,2-aminothiol functionalities are able to promote the cyclization of a downstream target peptide sequence via a C-terminal ligation/ring contraction mechanism. Using this approach, peptide macrocycles of variable size and composition could be generated in a pH-triggered manner in vitro or directly in living bacterial cells. This methodology furnishes a new platform for the creation and screening of genetically encoded libraries of conformationally constrained peptides. This strategy was applied to identify and isolate a low-micromolar streptavidin binder (KD = 1.1 μM) from a library of cyclic peptides produced in Escherichia coli, thereby illustrating its potential toward aiding the discovery of functional peptide macrocycles.

PDF emailed within 0-6 h: $19.90