Molecular cloning and characterization of a new Japanese cedar pollen allergen homologous to plant isoflavone reductase family.

Abstract

BACKGROUND:

Japanese cedar (Cryptomeria japonica) pollen is a major cause of seasonal pollinosis, and more than 10% of Japanese people suffer from this allergic disorder. However, only two major pollen allergens, Cry j 1 and Cry j 2, have been identified and exclusively characterized.

OBJECTIVE:

The aim of this study was to explore and identify important Japanese cedar pollen allergens other than Cry j 1 or Cry j 2.

METHODS:

C. japonica cDNA library was immunoscreened by rabbit antiserum raised against a partially purified cedar pollen allergen fraction. An isolated cDNA clone was inserted into a glutathione S-transferase (GST)-tagged Escherichia coli expression vector to obtain recombinant GST fusion protein. Non-fusion recombinant protein was purified by glutathione Sepharose affinity chromatography in conjunction with factor Xa cleavage of the GST moiety. IgE-binding ability of the recombinant protein was then evaluated by western blot analysis and enzyme-linked immunosorbent assay (ELISA).

RESULTS:

The cDNA encodes 306 amino acids with significant sequence similarity to those of plant isoflavone reductase-like proteins, which include a recently identified birch pollen allergen Bet v 5. Western blot analysis demonstrated that recombinant protein was recognized by cedar pollinosis patient IgE. In contrast to Bet v 5 being reported as a minor allergen, the recombinant protein exhibited 76% IgE binding frequency (19/25) against pollinosis patients.

CONCLUSION:

Here we identified the third member of Japanese cedar pollen allergen homologous to isoflavone reductase. Its high IgE-binding frequency implicates that the isoflavone reductase homologue might be an additional major pollen allergen in C. japonica.

• Authors: S Kawamoto, T Fujimura, M Nishida, T Tanaka, T Aki, M Masubuchi, T Hayashi, O Suzuki, S Shigeta, K Ono
• Journal: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology (Clin Exp Allergy) Vol. 32 Issue 7 Pg. 1064-70 (Jul 2002) ISSN: 0954-7894 [Print] England
• PMID: 12100055 (Publication Type: Journal Article)

Chemical References

• Allergens
• Recombinant Proteins
• Immunoglobulin E
• Oxidoreductases
• vestitone reductase
• Oxidoreductases Acting on CH-CH Group Donors

Topics

• Allergens (genetics, immunology, isolation & purification)
• Amino Acid Sequence
• Base Sequence
• Cloning, Molecular
• Cryptomeria (immunology)
• Escherichia coli (genetics)
• Immunoglobulin E (immunology)
• Molecular Sequence Data
• Molecular Weight
• Oxidoreductases (genetics, immunology)
• Oxidoreductases Acting on CH-CH Group Donors
• Pollen (immunology)
• Recombinant Proteins (isolation & purification)