title: Primary identification, biochemical characterization, and immunologic properties of the allergenic pollen cyclophilin cat R 1.
abstract: Cyclophilin (Cyp) allergens are considered pan-allergens due to frequently reported cross-reactivity. In addition to well studied fungal Cyps, a number of plant Cyps were identified as allergens (e.g. Bet v 7 from birch pollen, Cat r 1 from periwinkle pollen). However, there are conflicting data regarding their antigenic/allergenic cross-reactivity, with no plant Cyp allergen structures available for comparison. Because amino acid residues are fairly conserved between plant and fungal Cyps, it is particularly interesting to check whether they can cross-react. Cat r 1 was identified by immunoblotting using allergic patients' sera followed by N-terminal sequencing. Cat r 1 (∼ 91% sequence identity to Bet v 7) was cloned from a cDNA library and expressed in Escherichia coli. Recombinant Cat r 1 was utilized to confirm peptidyl-prolyl cis-trans-isomerase (PPIase) activity by a PPIase assay and the allergenic property by an IgE-specific immunoblotting and rat basophil leukemia cell (RBL-SX38) mediator release assay. Inhibition-ELISA showed cross-reactive binding of serum IgE from Cat r 1-allergic individuals to fungal allergenic Cyps Asp f 11 and Mala s 6. The molecular structure of Cat r 1 was determined by NMR spectroscopy. The antigenic surface was examined in relation to its plant, animal, and fungal homologues. The structure revealed a typical cyclophilin fold consisting of a compact β-barrel made up of seven anti-parallel β-strands along with two surrounding α-helices. This is the first structure of an allergenic plant Cyp revealing high conservation of the antigenic surface particularly near the PPIase active site, which supports the pronounced cross-reactivity among Cyps from various sources.
authors.affiliation: From the Bose Institute, 93/1 APC Road, Kolkata 700009, India, djghosh@yahoo.com.
authors.forename: Debajyoti
authors.initials: D
authors.lastname: Ghosh
authors.affiliation: the Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709.
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Mueller
authors.affiliation: the Research Centre Borstel, Leibniz Centre for Medicine and Biosciences, D-23845 Borstel, Germany, and.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Schramm
authors.affiliation: the Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709.
authors.forename: Lori L
authors.initials: LL
authors.lastname: Edwards
authors.affiliation: the Division of Clinical and Molecular Allergology, Research Center Borstel, Airway Research Center North (ARCN), Member of the German Centre for Lung Research, Parkallee 22, D-23845 Borstel, Germany.
authors.forename: Arnd
authors.initials: A
authors.lastname: Petersen
authors.affiliation: the Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709.
authors.forename: Robert E
authors.initials: RE
authors.lastname: London
authors.affiliation: the Research Centre Borstel, Leibniz Centre for Medicine and Biosciences, D-23845 Borstel, Germany, and.
authors.forename: Helmut
authors.initials: H
authors.lastname: Haas
authors.affiliation: From the Bose Institute, 93/1 APC Road, Kolkata 700009, India, swati@jcbose.ac.in.
authors.forename: Swati
authors.initials: S
authors.lastname: Gupta Bhattacharya
mesh_terms: D000328:Adult; D000485:Allergens / Q000737:chemistry* / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D016022:Case-Control Studies; D045744:Cell Line, Tumor; D002942:Circular Dichroism; D003429:Cross Reactions; D021983:Cyclophilins / Q000737:chemistry* / Q000276:immunology; D017931:DNA Primers; D018076:DNA, Complementary; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011058:Pollen / Q000737:chemistry* / Q000276:immunology; D051381:Rats; D017386:Sequence Homology, Amino Acid; D055815:Young Adult
chemical_list: D000485:Allergens; D017931:DNA Primers; D018076:DNA, Complementary; D021983:Cyclophilins
keywords: Allergen; Antibody; Antigen; Cloning; Cross-reactivity; Cyclophilin; Nuclear Magnetic Resonance (NMR); Protein Structure