title: Identification of novel allergenic components from German cockroach fecal extract by a proteomic approach.
abstract: BACKGROUND
  Cockroaches produce potent allergens, and cockroach feces are known to be especially rich in allergens. In this study, we analyze the allergenic components from cockroach feces and evaluate allergenicity of recombinant α-amylase identified from fecal extract.
  
  
  METHODS
  IgE-reactive proteins from German cockroach fecal extract were analyzed by proteomic analysis and immunoblotting. Recombinant α-amylase was produced and its allergenicity was evaluated by ELISA.
  
  
  RESULTS
  Analysis of German cockroach fecal extracts identified 12 IgE-reactive components. Most of these allergens were found to be digestive enzymes such as α-amylase, trypsin, chymotrypsin, metalloprotease, and midgut carboxypeptidase A, but the identity of 3 IgE-reactive proteins is still unknown. Glycinin-like proteins, which were likely derived from the cockroach diet, were also identified. German cockroach α-amylase shares the highest identity with pig α-amylase (55.8%), followed by mite group 4 allergens (Blo t 4, 50.4%; Der p 4, 49.8%; Eur m 4, 47.4%). In this study, recombinant α-amylase from German cockroach was expressed, and its allergenicity was examined by ELISA. Specific IgE against recombinant amylase was detected in 41.4% (12/29) of serum samples from German cockroach-sensitized subjects. Recombinant α-amylase was able to inhibit 55% of specific IgE to German cockroach whole-body extract.
  
  
  CONCLUSIONS
  Amylase was found to be an important novel allergen in cockroach feces. It is hoped that recombinant α-amylase will be useful for further studies and clinical applications.
authors.affiliation: Department of Internal Medicine and Institute of Allergy, Yonsei University College of Medicine, Seoul, Korea. jeongky@yuhs.ac
authors.forename: Kyoung Yong
authors.initials: KY
authors.lastname: Jeong
authors.forename: Chung-ryul
authors.initials: CR
authors.lastname: Kim
authors.forename: Jina
authors.initials: J
authors.lastname: Park
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Han
authors.forename: Jung-Won
authors.initials: JW
authors.lastname: Park
authors.forename: Tai-Soon
authors.initials: TS
authors.lastname: Yong
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D020048:Blattellidae / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000737:chemistry; D005260:Female; D006801:Humans; D006967:Hypersensitivity; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D019476:Insect Proteins / Q000276:immunology* / Q000302:isolation & purification; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D019076:Transgenes / Q000235:genetics; D055815:Young Adult; D000516:alpha-Amylases / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000485:Allergens; D019476:Insect Proteins; D007073:Immunoglobulin E; D000516:alpha-Amylases