IgE-binding Reactivity of Peptide Frag-ments of Bla g 1.02, a Major German Cockroach Allergen

• Published in: Asian Pacific journal of allergy and immunology Vol. 27; no. 2-3; p. 121
• Main Authors: Myung-hee, Yi, Kyoung Yong Jeong, Chung-Ryul, Kim, Tai-Soon, Yong
• Format: Journal Article
• Language: English
• Published: Bangkok The Allergy and Immunology Society 01.06.2009
• ISSN: 0125-877X

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 approxi-mately 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 ampli-fied and cloned. The full-length and five peptide fragments were overexpressed in Pichia pastoris and E. coli , re-spectively, and their IgE binding reactivities were measured by ELISA using 37 serum samples isolated from cock-roach-sensitized patients. The sera of 24 patients (64.9%) recognized the full-length Bla g 1.02 recombinant pro-tein. 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.