E-clonal antibodies: selection of full-length IgG antibodies using bacterial periplasmic display

Nat Protoc. 2008;3(11):1766-77. doi: 10.1038/nprot.2008.176.

Abstract

Here we describe a protocol for the selection of full-length IgG antibodies from repertoires displayed on Escherichia coli. In the method described here, full-length heavy and light chains are assembled in the periplasm into aglycosylated IgGs that are fully functional for antigen binding. Expression of an inner membrane-tethered Fc-binding protein is used to capture the IgG molecules and anchor them to the cell. Following outer-membrane permeabilization, fluorescently labeled ligand-binding library clones are selected by multiple rounds of fluorescence-activated cell sorting. Selection of a comprehensive set of IgG clones can typically be obtained within 3-4 weeks, a timescale that is comparable with most prevalent antibody display technologies. The isolated antibodies are well expressed in bacteria and exhibit affinities per binding site in the nanomolar range.

MeSH terms

  • Antibodies, Monoclonal / isolation & purification
  • Enzyme-Linked Immunosorbent Assay
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Immunoglobulin G / genetics
  • Immunoglobulin G / isolation & purification*
  • Peptide Library
  • Periplasm / genetics
  • Periplasm / metabolism
  • Plasmids / genetics
  • Protein Engineering / methods*
  • Recombinant Fusion Proteins / isolation & purification*

Substances

  • Antibodies, Monoclonal
  • Immunoglobulin G
  • Peptide Library
  • Recombinant Fusion Proteins