Characterization of a Birch Pollen Allergen, Bet v III, Representing a Novel Class of Ca2+ Binding Proteins: Specific Expression in Mature Pollen and Dependence of Patients' IgE Binding on Protein-Bound Ca2+

EMBO J. 1994 Aug 1;13(15):3481-6.

Abstract

A cDNA coding for a birch pollen allergen, Bet v III, with significant sequence homology to Ca2+ binding proteins was isolated from an expression cDNA library using serum IgE from a patient who was allergic to pollen. The deduced amino acid sequence of the pollen allergen contained three typical Ca2+ binding sites. Peptides mimicking the Ca2+ binding sites of Bet v III were synthesized and shown to bind 45Ca in blot overlays. The binding of patients' IgE to the recombinant allergen depended on the native protein conformation and protein-bound Ca2+. Depletion of Ca2+ led to a reversible loss of the IgE binding thus representing a conformational IgE epitope adopted by a polypeptide upon Ca2+ binding. By RNA hybridization it was demonstrated that Bet v III is expressed preferentially in mature pollen. Bet v III therefore represents a pollen allergen which because of its unique structural features also belongs to a novel class of Ca2+ binding proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / genetics*
  • Allergens / metabolism
  • Amino Acid Sequence
  • Antigens, Plant
  • Base Sequence
  • Binding Sites
  • Calcium / metabolism
  • Calcium-Binding Proteins / chemistry
  • Calcium-Binding Proteins / genetics*
  • Calcium-Binding Proteins / metabolism
  • Cloning, Molecular
  • DNA, Complementary
  • Epitopes / chemistry
  • Humans
  • Immunoglobulin E / metabolism*
  • Molecular Sequence Data
  • Peptides / chemical synthesis
  • Peptides / metabolism
  • Plant Proteins / chemistry
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Pollen / genetics*
  • Pollen / metabolism
  • Protein Conformation
  • RNA, Messenger / analysis
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Transcription, Genetic
  • Trees

Substances

  • Allergens
  • Antigens, Plant
  • Calcium-Binding Proteins
  • DNA, Complementary
  • Epitopes
  • Peptides
  • Plant Proteins
  • RNA, Messenger
  • BETVIII protein, Betula pendula
  • Immunoglobulin E
  • Calcium

Associated data

  • GENBANK/X79267