IgE-binding reactivity of peptide fragments of Bla g 1.02, a major German cockroach allergen.
Cockroaches cause allergic diseases and are closely linked with the development of asthma. Bla g 1 is one of the major allergen proteins produced by German cockroaches. It consists of tandem repeats of approximately 100 amino acids. The aim of the present study was to identify linear IgE-binding epitopes of Bla g 1.02. RT-PCR was used to clone a cDNA sequence encoding Bla g 1.02 (EF202179) which shared 98.6-99.8% identity with a previously reported Bla g 1.02 (AF072220). To investigate IgE binding regions, five separate but overlapping Bla g 1.02 peptide fragments (A: aa 1-111, B: aa 102-215, C: aa 206-299, D: aa 289-403, E: aa 394-491) were amplified and cloned. The full-length and five peptide fragments were overexpressed in Pichia pastoris and E. coli, respectively, and their IgE binding reactivities were measured by ELISA using 37 serum samples isolated from cockroach-sensitized patients. The sera of 24 patients (64.9%) recognized the full-length Bla g 1.02 recombinant protein. Among 19 selected serum samples, 11 sera (57.9%) reacted to peptide fragment A, 5 sera (31.3%) to B, 4 sera (21.1%) to C, 9 sera (47.4%) to D, and 10 sera (52.6%) to peptide fragment E. IgE-binding epitopes are found to be distributed to each tandem repeat of Bla g 1. The combination of peptide fragments A, D, and E may able to detect all Bla g 1-sensitized subjects. We suggest that these peptide fragments may be useful in allergy diagnosis and the design of novel immunotherapeutics.
Department of Environmental Medical Biology and Institute of Tropical Medicine, Arthropods of Medical Importance Resource Bank, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
Myung-Hee
MH
Yi
Kyoung Yong
KY
Jeong
Chung-Ryul
CR
Kim
Tai-Soon
TS
Yong
D000485:Allergens / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D052179:Antigens, Plant; D003001:Cloning, Molecular; D003058:Cockroaches / Q000276:immunology; D018604:Epitope Mapping; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D016056:Immunodominant Epitopes / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D007159:Immunologic Tests; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding
D000485:Allergens; D052179:Antigens, Plant; D016056:Immunodominant Epitopes; D010446:Peptide Fragments; C105482:allergen Bla g 1; D007073:Immunoglobulin E