Identification of distinct antibody epitopes and mimotopes from a peptide array of 5520 randomly generated sequences

J Immunol Methods. 2002 Sep 1;267(1):37-51. doi: 10.1016/s0022-1759(02)00139-4.

Abstract

We used a relatively small library of 5520 randomly generated single 15-mer peptides prepared by SPOT synthesis as an array of 28.5x19.0 cm to identify epitopes for three distinct monoclonal antibodies, namely anti-p24 (human immunodeficiency virus (HIV)-1) monoclonal anibody (mab) CB4-1, anti-interleukin-10 (IL-10) mab CB/RS/13, and anti-transforming growth factor alpha (TGFalpha) mab Tab2. Initially identified peptide ligands mostly had very low affinities for the antibodies with dissociation constants around 10(-4) M. Subsequent identification of residues critical for the antibody interactions involved complete L-amino acid substitutional analyses. Several substitutions resulted in analogs with dissociation constants in the low micromolar and high nanomolar range. Specifically binding peptides with key residue patterns matching the wild-type epitopes were identified for all three antibodies. In addition, for antibody CB4-1 mimotopes that showed no homology to the known epitope were selected. Our results suggest that a very limited library diversity, although far from covering the entire sequence repertoire, can suffice to rapidly and economically select peptidic antibody epitopes and mimotopes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Combinatorial Chemistry Techniques*
  • Enzyme-Linked Immunosorbent Assay
  • Epitope Mapping / methods*
  • Epitope Mapping / trends
  • Epitopes
  • Peptide Biosynthesis / immunology*
  • Peptide Library*

Substances

  • Epitopes
  • Peptide Library