Rapid screening for potential epitopes reactive with a polycolonal antibody by solution-phase H/D exchange monitored by FT-ICR mass spectrometry

J Am Soc Mass Spectrom. 2013 Jul;24(7):1016-25. doi: 10.1007/s13361-013-0644-7. Epub 2013 May 17.

Abstract

The potential epitopes of a recombinant food allergen protein, cashew Ana o 2, reactive to polyclonal antibodies, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Ana o 2 polyclonal antibodies were purified in the serum from a goat immunized with cashew nut extract. Antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen:polyclonal antibody (Ag:pAb) complexes. Complexed and uncomplexed (free) rAna o 2 were then subjected to HDX-MS analysis. Four regions protected from H/D exchange upon pAb binding are identified as potential epitopes and mapped onto a homologous model.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Allergens / chemistry
  • Allergens / genetics
  • Amino Acid Sequence
  • Anacardium / chemistry
  • Anacardium / genetics
  • Anacardium / immunology
  • Animals
  • Antibody Specificity
  • Antigen-Antibody Complex / chemistry
  • Antigens, Plant / chemistry*
  • Antigens, Plant / genetics
  • Cyclotrons
  • Deuterium Exchange Measurement / methods*
  • Epitope Mapping / methods*
  • Epitopes / chemistry*
  • Epitopes / genetics
  • Fourier Analysis
  • Goats
  • Models, Molecular
  • Molecular Sequence Data
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Protein Subunits
  • Spectrometry, Mass, Electrospray Ionization / methods*

Substances

  • Allergens
  • Ana o 2 allergen, cashew
  • Antigen-Antibody Complex
  • Antigens, Plant
  • Epitopes
  • Peptide Fragments
  • Protein Subunits