Bacterial Cell-Surface Display of Semisynthetic Cyclic Peptides.
Semisynthetic cyclic peptides containing both non-proteinogenic building blocks, as the synthetic part, and a genetically encoded sequence amenable to DNA-based randomization hold great potential to expand the chemical space in the quest for novel bioactive peptides. Key to an efficient selection of novel binders to biomacromolecules is a robust method to link their genotype and phenotype. A novel bacterial cell surface display technology has been developed to present cyclic peptides composed of synthetic and genetically encoded fragments in their backbones. The fragments were combined by protein trans-splicing and intramolecular oxime ligation. To this end, a split intein half and an unnatural amino acid were displayed with the genetically encoded part on the surface of Escherichia coli. Addition of the synthetic fragment equipped with the split intein partner and an aminooxy moiety, as well as the application of a pH-shift protocol, resulted in the onsurface formation of the semisynthetic cyclic peptide. This approach will serve for the generation of cyclic peptide libraries suitable for selection by fluorescence-activated cell sorting, and more generally enables chemical modification of proteins on the bacterial surface.
['Palei|Shubhendu|S|0000-0003-4447-7022', 'Becher|Kira S|KS|', 'Nienberg|Christian|C|', 'Jose|Joachim|J|', 'Mootz|Henning D|HD|0000-0002-3385-0234']
D061505:Cell Surface Display Techniques D003500:Cyclization D004926:Escherichia coli D010091:Oximes D019151:Peptide Library D010456:Peptides, Cyclic D015202:Protein Engineering D020040:Trans-Splicing
oxime ligation inteins bacterial display macrocycles semisynthesis