Korean J Parasitol.  2009 Mar;47(1):31-36. 10.3347/kjp.2009.47.1.31.

IgE Binding Reactivity of Peptide Fragments of Bla g 4, a Major German Cockroach Allergen

• Shin KH
• Jeong KY
• Hong CS
• Yong TS

• KMID: 1720606
• DOI: http://doi.org/10.3347/kjp.2009.47.1.31

Abstract

Cockroaches have been recognized as a major cause of asthma. Bla g 4 is one of the most important German cockroach allergens. The aim of this study is to investigate IgE reactivity to the recombinant Bla g 4 (rBla g 4) in the sera of allergic patients and identify linear IgE binding epitope. For protein expression, full-length Bla g 4 (EF202172) was divided into 5 overlapping peptide fragments (E1: aa 1-100, E2: aa 34-77, E3: aa 74-117, E4: aa 114-156, and E5: aa 153-182). The full-length and 5 peptide fragments of Bla g 4 was generated by PCR and over-expressed in E. coli BL21 (DE3). The IgE binding reactivities of the full-length and peptide fragments were measured by ELISA using 32 serum samples of cockroach allergy. The sera of 8 patients (25%) reacted with rBla g 4. Four sera (100%) showed IgE-binding reactivity to full-length and peptide fragment 4, and 2 sera (50%) reacted with peptide fragment 2. One (20%) serum reacted with peptide fragment 3. The results of ELISA using overlapping recombinant fragments indicated that the epitope region was located at amino acid sequences 34-73 and 78-113, and major IgE epitope of Bla g 4 was located at amino acid sequences 118-152 of C-terminal. B-cell epitope analysis of German cockroach allergen Bla g 4 could contribute to the strategic development of more specific and potentially efficacious immunotherapy.

Keyword

Blattella germanica; Allergen; B-cell epitope; IgE; lipocalin

MeSH Terms

Adolescent
Adult
Allergens/chemistry/genetics/*immunology
Amino Acid Sequence
Animals
Child
Cockroaches/*immunology
*Epitope Mapping
Escherichia coli/genetics/metabolism
Female
Humans
Hypersensitivity/*immunology
Immunoglobulin E/*immunology
Insect Proteins/chemistry/genetics/*immunology
Male
Middle Aged
Molecular Sequence Data
Sequence Alignment
Young Adult