Isolation and characterization of a cDNA clone encoding one IgE-binding fragment of Penicillium brevicompactum.
BACKGROUND
The abundance of allergenic Penicillium species has been associated with an increased incidence of childhood asthma and pulmonary bleeding. Penicillium brevicompactum has been identified as the most prevalent indoor species of this genus. However, detailed studies on the allergens of the ubiquitous Penicillium species are still lacking. For the characterization of allergens of prevalent Penicillium species, molecular cloning of the allergen genes of P. brevicompactum was performed in the present study.


METHODS
A phage cDNA library of P. brevicompactum was constructed in Uni-ZAP XR vector using mRNA isolated from the organism. The cDNA library of P. brevicompactum was screened using pooled atopic sera.


RESULTS
Screening of P. brevicompactum cDNA library resulted in one positive clone encoding an estimated molecular weight of 11 kDa polypeptide, rich in acidic residues (>20%), with a pI of 3.87. This clone was designated as Pen b 26 and found to be reactive only against the atopic sera obtained from individuals sensitive to P. brevicompactum. The amino acid sequence analysis of Pen b 26 revealed that it had strong homology to the 60S acidic ribosomal protein P1 family from different eukaryotic sources, predominantly fungal aero-allergens. Other features of Pen b 26 including having high alpha-helical content (>50%), alanine-rich residues (>20%), and a well-conserved C-terminal epitope region fits well into the common properties of 60S acidic ribosomal proteins.


CONCLUSIONS
The results obtained suggest that the allergenic clone, Pen b 26 is a 60S acidic ribosomal protein P1 of P. brevicompactum and shows strong similarity to other P1 family proteins.
Sevinc
M Serdal
MS
Environmental Health Directorate, F.G. Banting Building, Health Canada, Tunney's Pasture, Ottawa, Ontario K1A 0L2, Postal Locator 2202D2, Canada.
Kumar
Veena
V
Abebe
Makonnen
M
Casley
William L
WL
Vijay
Hari M
HM
D000595:Amino Acid Sequence; D000818:Animals; D000946:Antigens, Fungal / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification*; D015723:Gene Library; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D010407:Penicillium / Q000235:genetics* / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D000946:Antigens, Fungal; D018076:DNA, Complementary; D007073:Immunoglobulin E