IgE binding epitopes of Bla g 6 from German cockroach.
Bla g 6, a German cockroach allergen, shows homology to muscle protein troponin C. It contains four calcium-binding domains at amino acid (aa) residues 20-30, 56-67, 96-107, and 132-143, and its immunoglobulin E (IgE) reactivity is dependent upon calcium ion level. However, the IgE binding epitopes of Bla g 6 have not been investigated. This study aimed to analyze the IgE binding epitopes from the five peptide fragments of Bla g 6. The full-length of three Bla g 6 isoallergens (Bla g 6.0101, Bla g 6.0201, and Bla g 6.0301) and five peptide fragments (P1: aa 1-111, P2: aa 1-95, P3: aa 33-111, P4: aa 80-151, and P5: aa 33-151) of Bla g 6.0101 were generated by polymerase chain reaction (PCR) and expressed in Escherichia coli. Enzyme-linked immunosorbent assay (ELISA) was performed on 24 patients' sera that adjusted the final concentration 10 mM of CaCl(2) to determine the IgE activities of Bla g 6. Eight sera (33.3%), 9 sera (37.5%), and 11 sera (45.8%) showed IgE reactivity to Bla g 6.0101, Bla g 6.0201, and Bla g 6.0301, respectively. Among the sera from the positive IgE reactivity, three patients' sera were selected and the IgE reactivity was measured by ELISA with the five peptide fragments of Bla g 6. Based on IgE responses, one patient's serum exhibited the strongest IgE reactivity. We assumed that the aa between 96-151 residues, including the calcium binding domains III and IV, would be important for IgE binding. These results may provide information that will yield safe diagnostic methods and immunotherapeutics.
Un
Sunjin
S
Department of Environmental Medical Biology and Institute of Tropical Medicine, Korea National Arthropods of Medical Importance Resource Bank, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
Jeong
Kyoung Yong
KY
Yi
Myung-hee
MH
Kim
Chung-ryul
CR
Yong
Tai-Soon
TS
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002648:Child; D003058:Cockroaches / Q000276:immunology*; D000939:Epitopes / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019209:Troponin C / Q000378:metabolism; D055815:Young Adult
D000485:Allergens; D002135:Calcium-Binding Proteins; D000939:Epitopes; D019209:Troponin C; D007073:Immunoglobulin E