title: Structural characteristics of the Ascaris allergen, ABA-1.
abstract: The structure of the Ascaris allergen, ABA-1 was characterized at several levels. Purified allergen monomers eluted from reducing PAGE were found to reassociate into dimers in phosphate buffered saline containing 0.9 mM Ca2+. This association may involve the formation of disulfide bonds between monomers. The primary amino acid sequence was used to predict secondary structure and compare the allergen to other known proteins sequences. ABA-1 appears to be highly helical protein of two domains. Sequence analysis reveals short regions (25 amino acids) of high homology (76%) between ABA-1 and the major body wall myosin of Onchocerca volvulus. In addition, ABA-1 has sequence similarity to a family of EF-hand containing calcium binding proteins called S100 proteins. The dimerization and two-domain structure of ABA-1 is consistent with the possibility that ABA-1 is a member of the S100 family of calcium binding proteins.
authors.affiliation: Department of Microbiology and Infectious Diseases, University of Calgary, Alberta, Canada.
authors.forename: A M
authors.initials: AM
authors.lastname: McGibbon
authors.forename: T D
authors.initials: TD
authors.lastname: Lee
mesh_terms: D000485:Allergens / Q000737:chemistry*; D000818:Animals; D000947:Antigens, Helminth / Q000737:chemistry*; D052179:Antigens, Plant; D001200:Ascaris / Q000737:chemistry* / Q000276:immunology; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D017124:Conserved Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D015801:Helminth Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017433:Protein Structure, Secondary; D009418:S100 Proteins / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012984:Software
chemical_list: C093689:ABA-1 protein, Ascaris suum; D000485:Allergens; D000947:Antigens, Helminth; D052179:Antigens, Plant; D015801:Helminth Proteins; D009418:S100 Proteins; C072337:S100A11 protein, human