title: Purification and characterization of Par o I, major allergen of Parietaria officinalis pollen.
abstract: Par o I, a major allergen of Parietaria officinalis, was purified from the pollen extract. The purified allergen was obtained by ultrafiltration, Sephadex gel filtration and DE-52 ion exchange chromatography: the purified preparation yields a single band in polyacrylamide gel isoelectric focusing (PAG-IEF), sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting, a single immunoprecipitation arc in crossed immunoelectrophoresis (CIE) and crossed radioimmunoelectrophoresis (CRIE) and a single peak in size exclusion high-performance liquid chromatography (HPLC). Par o I is a glycoprotein with a protein to carbohydrate ratio of 100:21. The molecular weight, determined by SDS-PAGE, Sephadex G-50 gel filtration and size exclusion HPLC, varied between 13.5 and 14.5 kDa according to the method employed. The isoelectric point was 4.6. The amino acid composition and the sequence of the first twelve N-terminal residues were determined. The allergenicity was assayed in vivo and in vitro. 29/29 Parietaria-allergic patients were skin positive to Par o I and possessed high level of specific serum IgE antibody as it determined by radioallergosorbent test (RAST). Par o I contained dominant epitopes for human IgE as inhibited to 85% the pollen extract RAST performed with a pool of sera of allergic patients. The RAST inhibitory activity was not abolished by deglycosylation.
authors.affiliation: Institute of Protein Biochemistry and Enzymology, CNR, Napoli, Italia.
authors.forename: U
authors.initials: U
authors.lastname: Oreste
authors.forename: M R
authors.initials: MR
authors.lastname: Coscia
authors.forename: A
authors.initials: A
authors.lastname: Scotto d'Abusco
authors.forename: V
authors.initials: V
authors.lastname: Santonastaso
authors.forename: A
authors.initials: A
authors.lastname: Ruffilli
mesh_terms: D000485:Allergens / Q000737:chemistry / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D000818:Animals; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007122:Immunoelectrophoresis; D007073:Immunoglobulin E / Q000032:analysis; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification*; D011058:Pollen; D011817:Rabbits; D012882:Skin Tests
chemical_list: D000485:Allergens; D006023:Glycoproteins; C072038:Par o I protein, Parietaria officinalis; D010940:Plant Proteins; D007073:Immunoglobulin E