title: Mapping of IgE and IgG4 antibody-binding epitopes in Cyn d 1, the major allergen of Bermuda grass pollen.
abstract: BACKGROUND
  Bermuda grass pollen (BGP) is an important seasonal aeroallergen worldwide which induces allergic disorders such as allergic rhinitis, conjunctivitis and asthma. Cyn d 1 is the major allergen of BGP. This study is aimed to map human IgE and IgG(4) antibody-binding sequential epitopes on Cyn d 1 by dot immunoblotting.
  
  
  METHODS
  Synthetic peptides (10-mers; 5 overlapping residues) spanning the full length of Cyn d 1 were used for dot immunoblotting to map human IgE and IgG(1-4) antibody-binding regions with sera from BGP-allergic patients. Synthetic peptides with more overlapping residues were used for further mapping. Essential amino acids in each epitope were examined by single amino acid substitution with alanine. Peptides with sequence polymorphism of epitopes of Cyn d 1 were also synthesized to extrapolate their differences in binding capability.
  
  
  RESULTS
  Four major IgE-binding epitopes (peptides 15(-1), 21, 33(-2) and 35(+1), corresponding to amino acids 70-79, 101-110, 159-167 and 172-181) and 5 major IgG(4)-binding epitopes (peptides 15(-1), 30(-2), 33(-2), 35(+1) and 39, corresponding to amino acids 70-79, 144-153, 159-167, 172-181 and 192-200) were identified. They are all located on the surface of the simulated Cyn d 1 molecule, and three of them are major epitopes for both IgE and IgG(4). Their critical amino acids were all characterized. Major epitopes for human IgG(1) to IgG(4) are almost identical.
  
  
  CONCLUSIONS
  This is the first study to map the sequential epitopes for human IgE and IgG(4) subclasses in Cyn d 1. It will be helpful for future development in immunotherapy and diagnosis.
authors: Children's Medical Center, Taipei Veterans General Hospital, Taipei, Taiwan.
authors: Han-Chih
authors: HC
authors: Yuan
authors: Keh-Gong
authors: KG
authors: Wu
authors: Chun-Jen
authors: CJ
authors: Chen
authors: Song-Nan
authors: SN
authors: Su
authors: Horng-Der
authors: HD
authors: Shen
authors: Yann-Jang
authors: YJ
authors: Chen
authors: Ho-Jen
authors: HJ
authors: Peng
mesh_terms: D000485:Allergens / Q000737:chemistry* / Q000276:immunology*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D052179:Antigens, Plant / Q000737:chemistry* / Q000276:immunology*; D003429:Cross Reactions / Q000276:immunology; D031744:Cynodon / Q000276:immunology; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007073:Immunoglobulin E / Q000737:chemistry* / Q000276:immunology; D007074:Immunoglobulin G / Q000737:chemistry* / Q000276:immunology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011058:Pollen / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D011487:Protein Conformation
chemical_list: D000485:Allergens; D052179:Antigens, Plant; C550205:Cyn d 1 allergen, Bermuda grass; D000939:Epitopes; D007074:Immunoglobulin G; D007073:Immunoglobulin E