Dissecting antibodies with regards to linear and conformational epitopes

PLoS One. 2015 Mar 27;10(3):e0121673. doi: 10.1371/journal.pone.0121673. eCollection 2015.

Abstract

An important issue for the performance and specificity of an antibody is the nature of the binding to its protein target, including if the recognition involves linear or conformational epitopes. Here, we dissect polyclonal sera by creating epitope-specific antibody fractions using a combination of epitope mapping and an affinity capture approach involving both synthesized peptides and recombinant protein fragments. This allowed us to study the relative amounts of antibodies to linear and conformational epitopes in the polyclonal sera as well as the ability of each antibody-fraction to detect its target protein in Western blot assays. The majority of the analyzed polyclonal sera were found to have most of the target-specific antibodies directed towards linear epitopes and these were in many cases giving Western blot bands of correct molecular weight. In contrast, many of the antibodies towards conformational epitopes did not bind their target proteins in the Western blot assays. The results from this work have given us insights regarding the nature of the antibody response generated by immunization with recombinant protein fragments and has demonstrated the advantage of using antibodies recognizing linear epitopes for immunoassay involving wholly or partially denatured protein targets.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / immunology*
  • Chromatography, Affinity / methods*
  • Epitope Mapping / methods*
  • Epitopes / chemistry*
  • Epitopes / metabolism*
  • Humans
  • Immunization
  • Models, Molecular
  • Peptides / chemistry
  • Peptides / immunology
  • Protein Structure, Tertiary
  • Rabbits
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / immunology

Substances

  • Antibodies
  • Epitopes
  • Peptides
  • Recombinant Proteins

Grant support

Funding was provided by the Knut and Alice Wallenberg Foundation (https://www.wallenberg.com/Kaw/en). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.