Construction of the fundamental data for the clinical test of the allergy patients' substituted foods

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 12680128
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 食生活
• Research Institution: NIIGATA UNIVERSITY
• Principal Investigator: ODANI Sumiko NIIGATA UNIVERSITY Faculty of Education and Human Sciences Professor, 教育人間科学部, 教授 (60018653)
• Project Period (FY): 2000 – 2002
• Keywords: allergy / substituted food / hen egg / Japanese quail egg / ovalbumin / ovomucoid / antigenicity / epitope

Research Abstract

Ovalbumin (OVA) and ovomucoid (OM) are major allergens of hen's egg white and often induce hypersensitivity in atopic children. The sequence homology of Japanese quail (JQ) egg OVA^<1)> or OM^<2)> and hen (H) egg OVA^<3)> or OM^<4)> is 88.9% or 75.8% respectively. But the binding activities of JQ-OVA to rabbit anti H-OVA serum and JQ-OM to anti H-OM serum, measured by the method of inhibition ELISA, were 6.8% and 0.04% respectively. These results indicate that the antigenicity decreases dramatically when a few amino acid residues replace each other. This study aimed to characterize the antigenic determinants of JQ-OVA by immunoblotting and microsequence analysis methods. For this purpose, JQ-OVA was isolated from the JQ egg white by the fractionation with ammonium sulfate and gel filtration chromatography. The rabbit anti JQ-OVA serum was prepared by injecting the purified JQ-OVA to a female rabbit. JQ-OVA was digested with S. aureus V8 protease, TPCK-trypsin, TLCK-chymotrypsin and pepsin, and the peptides were separated with tricine SDS-polyacrylamide gel electrophoresis and two-dimentional gel electrophoresis. The antigenicity was tested by binding an anti JQ-OVA rabbit IgG antibody with the peptides. It is proposed that a part of the antigenic determinant (or epitope) existed in the JQ-OVA sequences of 17-28, 72-84, 1 20-124, 132-149, 160-175, 206-211, 219-226, 233-242, 244-253 and 298-308. These epitopes differed from those of H-OVA. Furthermore, baby foods (chawan-musi, custard pudding egg bouro, and kakitama soup) were cooked with JQ-egg and H-egg. A sensory test revealed that there were no differences between these baby foods cooked with JQ-egg and H-egg. Those results will allow better treatment to be provided for the hen egg allergy.
1)Nisbet, et al. 1981 Eur. J. Biochem, 115, 335-345, 2)Kato, et al. 1987 Biochemistry, 26, 193-201
3)Mucha,et al. 1990 Nucleic Acids Res., 18, 5553. 4)Papamakos, et al. 1982 J. Ml. Biol., 158, 515-537