Molecular and structural analysis of a continuous birch profilin epitope defined by a monoclonal antibody

Petra Wiedemann, Klaudia Giehl, Steven C. Almo, Alexander A. Fedorov, Mark Girvin, Peter Steinberger, Manfred Rüdiger, Maria Ortner, Manfred Sippl, Christiane Dolecek, Dietrich Kraft, Brigitte Jockusch, Rudolf Valenta

Research output: Contribution to journalArticle

40 Scopus citations

Abstract

The interaction of a mouse monoclonal antibody (4A6) and birch profilin, a structurally well conserved actin- and phosphoinositide-binding protein and cross-reactive allergen, was characterized. In contrast to serum IgE from allergic patients, which shows cross-reactivity with most plants, monoclonal antibody 4A6 selectively reacted with tree pollen profilins. Using synthetic overlapping peptides, a continuous hexapeptide epitope was identified. The exchange of a single amine acid (Gln-47→Glu) within the epitope was found to abolish the binding of monoclonal antibody 4A6 to other plant profilins. The NMR analyses of the birch and the nonreactive timothy grass profilin peptides showed that the loss of binding was not due to major structural differences. Both peptides adopted extended conformations similar to that observed for the epitope in the x-ray crystal structure of the native birch profilin. Binding studies with peptides and birch profilin mutants generated by in vitro mutagenesis demonstrated that the change of Gln-47 to acidic amino acids (e.g. Glu or Asp) led to electrostatic repulsion of monoclonal antibody 4A6. In conclusion the molecular and structural analyses of the interaction of a monoclonal antibody with a continuous peptide epitope, recognized in a conformation similar to that displayed on the native protein, are presented.

Original languageEnglish (US)
Pages (from-to)29915-29921
Number of pages7
JournalJournal of Biological Chemistry
Volume271
Issue number47
DOIs
Publication statusPublished - Nov 30 1996

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this