Cloning, sequencing and immunological characterization of Dac g 3, a major allergen from Dactylis glomerata pollen

Mol Immunol. 1996 Jun;33(9):797-806. doi: 10.1016/0161-5890(96)00015-6.


Preliminary work showed that a 14-kDa allergen with a pI of 9 was recognized by more than 60% of sera from Dactylis glomerata (Dac g) pollen-allergic individuals. The N-terminal amino acid sequence of this Dac g allergen was determined by Edman degradation and compared with that of Lol p 3, a major allergen of Lolium perenne. A sequence identity of 65% was found, suggesting that the Dac g allergen could be the homologue of Lol p 3 and therefore named Dac g 3. We report the cloning and sequence analysis of a cDNA encoding the Dac g 3 pollen allergen. The recombinant allergen (rDac g 3) expressed in plasmid vector pGEX-2T contained IgE-reactive epitopes found in its natural counterpart, and induced histamine release from basophils of Dac g-allergic individuals, confirming that the recombinant protein has biological properties similar to the pollen extracted allergen. Computer analyses showed that, in spite of a high degree of sequence homology, even closely related allergens such as Dac g 3 and Lol p 3 have dissimilar predictive secondary structures and potential different antigenicity. Because it possesses the properties of the native counterpart, rDac g 3 could be a relevant tool for molecular studies in allergy.

MeSH terms

  • Allergens / chemistry
  • Allergens / genetics*
  • Allergens / isolation & purification*
  • Amino Acid Sequence
  • Antigens, Plant
  • Base Sequence
  • Cloning, Molecular
  • Cross Reactions
  • DNA, Complementary / isolation & purification
  • Electrophoresis, Gel, Two-Dimensional
  • Histamine Release
  • Humans
  • Molecular Sequence Data
  • Plant Proteins / chemistry
  • Plant Proteins / genetics*
  • Plant Proteins / isolation & purification*
  • Poaceae / immunology*
  • Pollen / immunology*
  • Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid


  • Allergens
  • Antigens, Plant
  • DNA, Complementary
  • Dac g 3 allergen
  • Plant Proteins

Associated data

  • GENBANK/U25343