title: Characterization of proteases, proteins, and eicosanoid-like substances in soluble extracts from allergenic pollen grains.
abstract: BACKGROUND
  Pollen is an important trigger of seasonal rhinitis, conjunctivitis, and/or allergic asthma, and an exacerbating factor in atopic dermatitis. Pollen grains contain allergen proteins, enzymes, and bioactive lipid mediators, the latter two possibly involved in the pathogenesis of allergic diseases through IgE-independent mechanisms.
  
  
  METHODS
  We analyzed the patterns of release of endopeptidases from allergenic pollen of Japanese cedar, Japanese cypress, and Rocky mountain juniper, which belong to the Cupressaceae/Taxodiaceae family, and birch, ragweed, and two grasses, Kentucky blue and cultivated rye, using synthetic substrates, class-specific inhibitors, and zymography. The proteins released were analyzed by gel electrophoresis. Eicosanoid-like substances were measured by enzyme-linked immunosorbent assays for prostaglandin E(2) and leukotriene B(4).
  
  
  RESULTS
  Major fractions of proteins, eicosanoid-like substances, and at least one molecular species of serine endopeptidase were released into phosphate-buffered saline from the pollen grains at 37 degrees C within 25 min or 60 min without sonication. In the Cupressaceae/Taxodiaceae family, sonication was necessary for the release of other proteins and another serine endopeptidase. In birch, ragweed, and the grasses, most of the serine and cysteine endopeptidases were released without sonication. Proteases released within 25 min digested gelatin and/or casein differently among plant species.
  
  
  CONCLUSIONS
  Grains of allergenic pollen release proteases, which can digest not only short synthetic substrates but also protein substrates, along with eicosanoid-like substances and proteins. The release of these components could contribute to the formation of a microenvironment optimum for initiation of the sensitization or the exacerbation of pollen allergy in tissues exposed to pollen grains.
authors.affiliation: Atopy (Allergy) Research Center, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Hendra
authors.initials: H
authors.lastname: Gunawan
authors.forename: Toshiro
authors.initials: T
authors.lastname: Takai
authors.forename: Seiji
authors.initials: S
authors.lastname: Kamijo
authors.forename: Xiao Ling
authors.initials: XL
authors.lastname: Wang
authors.forename: Shigaku
authors.initials: S
authors.lastname: Ikeda
authors.forename: Ko
authors.initials: K
authors.lastname: Okumura
authors.forename: Hideoki
authors.initials: H
authors.lastname: Ogawa
mesh_terms: D000485:Allergens / Q000737:chemistry*; D031164:Ambrosia / Q000276:immunology; D029662:Betula / Q000276:immunology; D032485:Cryptomeria / Q000276:immunology; D029781:Cupressus / Q000276:immunology; D015232:Dinoprostone / Q000032:analysis; D004229:Dithiothreitol / Q000494:pharmacology; D015777:Eicosanoids / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D007975:Leukotriene B4 / Q000032:analysis; D010447:Peptide Hydrolases / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry*; D011058:Pollen; D013450:Sulfones / Q000494:pharmacology
chemical_list: D000485:Allergens; D015777:Eicosanoids; D010936:Plant Extracts; D013450:Sulfones; D007975:Leukotriene B4; C002010:4-(2-aminoethyl)benzenesulfonylfluoride; D010447:Peptide Hydrolases; D015232:Dinoprostone; D004229:Dithiothreitol