Purification, identification, and cDNA cloning of Cha o 2, the second major allergen of Japanese cypress pollen

Biochem Biophys Res Commun. 1999 Sep 16;263(1):166-71. doi: 10.1006/bbrc.1999.1261.


The second major allergen of Chamaecyparis obtusa (Japanese cypress) pollen, Cha o 2, has been purified and its cDNA cloned. Of patients with pollinosis caused by C. obtusa, 82.5% produce IgE antibodies which react with purified Cha o 2. The purified protein has a molecular mass of 46 kDa and its 12 N-terminal amino acid sequence displays a high homology with that of Cry j 2, the second major allergen of Cryptomeria japonica pollen. cDNA clones coding for Cha o 2 have been isolated using Cry j 2 cDNA as a probe. Cha o 2 cDNA clones were sequenced and found to code a putative 50-residue signal sequence and a 464-residue mature protein with a molecular weight of 50 kDa. Two possible N-linked glycosylation sites were found in the sequence. The deduced amino acid sequence of Cha o 2 shows 74.3% identity with that of Cry j 2. In its primary structure, Cha o 2 shows significant identity with those of the polygalacturonases of avocado, tomato, and maize as well as Cry j 2.

MeSH terms

  • Allergens / chemistry
  • Allergens / genetics*
  • Allergens / isolation & purification*
  • Amino Acid Sequence
  • Antibody Specificity
  • Base Sequence
  • Case-Control Studies
  • Cloning, Molecular
  • DNA, Complementary / genetics*
  • DNA, Plant / genetics
  • Humans
  • Immunoglobulin E / blood
  • Molecular Sequence Data
  • Molecular Weight
  • Plant Proteins / genetics
  • Plant Proteins / immunology
  • Pollen / chemistry
  • Pollen / genetics*
  • Pollen / immunology*
  • Rhinitis, Allergic, Seasonal / immunology
  • Sequence Homology, Amino Acid
  • Trees


  • Allergens
  • Cry j II protein, Cryptomeria japonica
  • DNA, Complementary
  • DNA, Plant
  • Plant Proteins
  • Immunoglobulin E