title: Identification of immunoglobulin E (IgE)-binding epitopes and recombinant IgE reactivities of a latex cross-reacting Indian jujube Ziz m 1 allergen.
abstract: Ziz m 1 is a major Indian jujube (Zizyphus mauritiana) allergen involved in latex-fruit syndrome, and cDNA of the allergen has been cloned, sequenced and expressed in yeast by our laboratory previously. In this study, we performed an immunoglobulin E (IgE)-binding epitope analysis of Ziz m 1 using overlapping recombinant fragments. Eight overlapping recombinant fragments were generated from the recombinant Ziz m 1 allergen. The fragments were expressed in Escherichia coli and IgE-binding activities were evaluated by sera of latex-Indian jujube-allergic subjects and normal subjects using immunoblotting. Human allergic sera are not able to recognize fragments consisting of amino acid sequences 26-71, 119-280 and 119-291. However, residues at positions 26-199, 26-105, 26-86, 119-320 and 238-330 were found relevant in the IgE-binding. Our results indicate that (72)NISGHCSDCTFLGEE(86) and (292)VWNRYYDLKTNYSSSIILEYVNSGTKYLP(320) of Ziz m 1 are the sequences required for human IgE binding. Four corresponding peptides, (72)NISGHCSDCTE(86), (292)VWNRYYDLKT(301), (300)KTNYSSSIILEY(311) and (309)LEYVNSGTKYLP(320), were synthesized, and these peptides reacted with 70%, 100%, 70% and 70% of 10 allergic sera tested, as revealed by enzyme-linked immunosorbent assay. Sensitization to (292)VWNRYYDLKT(301) correlated significantly with the presence of allergic symptoms (P < 0.001). These findings will be useful in designing diagnostic and therapeutic approaches, thereby contributing to the development of specific immunotherapy for subjects with latex-fruit syndrome.
authors.affiliation: Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: M F
authors.initials: MF
authors.lastname: Lee
authors.forename: J J
authors.initials: JJ
authors.lastname: Tsai
authors.forename: G Y
authors.initials: GY
authors.lastname: Hwang
authors.forename: S J
authors.initials: SJ
authors.lastname: Lin
authors.forename: Y H
authors.initials: YH
authors.lastname: Chen
mesh_terms: D000485:Allergens / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D052179:Antigens, Plant; D003429:Cross Reactions; D000939:Epitopes / Q000032:analysis* / Q000276:immunology; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism*; D020315:Latex Hypersensitivity / Q000276:immunology*; D010446:Peptide Fragments / Q000378:metabolism; D010936:Plant Extracts / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology*; D016133:Polymerase Chain Reaction / Q000379:methods; D011994:Recombinant Proteins / Q000378:metabolism; D012882:Skin Tests / Q000379:methods; D031957:Ziziphus / Q000276:immunology*
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D000939:Epitopes; D010446:Peptide Fragments; D010936:Plant Extracts; D010940:Plant Proteins; D011994:Recombinant Proteins; C530173:Ziz m 1 protein, Indian jujube; D007073:Immunoglobulin E