Identification of sequential IgE-binding epitopes on bovine alpha(s2)-casein in cow's milk allergic patients.
BACKGROUND
Caseins are the major allergens responsible for cow's milk allergy (CMA). We have previously identified the IgE-binding epitopes of the major cow's milk (CM) proteins except for alpha(s2)-casein.


METHODS
Overlapping decapeptides representing the entire length of alpha(s2)-casein were synthesized on a cellulose-derivatized membrane. Sera from 13 CM-allergic children, 4-15 years of age, with a median level of CM-specific IgE >100 kU/l (range 33.7 to > 100 kU/l) were used to identify IgE-binding epitopes.


RESULTS
Four major and six minor sequential IgE-binding regions were identified on alpha(s2)-casein. The first major region is located in the middle of the protein at amino acids (AA) 83-100, and the other three major regions are located in the carboxy terminal portion of the protein at AA 143-158, 157-172 and 165-188. The minor IgE-binding regions were identified at AA 31-44, 43-56, 93-106, 105-114, 117-128, and 191-200.


CONCLUSIONS
We identified 10 sequential IgE-binding regions on alpha(s2)-casein and performed the first crucial step in the development of immunotherapeutic interventions for CMA.
Busse
Paula J
PJ
Department of Pediatrics, Division of Allergy and Immunology, Jaffe Institute for Food Allergy, The Mount Sinai School of Medicine, 1 Gustave L. Levy Place, New York, NY 10029-6574, USA.
Järvinen
Kirsi-Marjut
KM
Vila
Leticia
L
Beyer
Kirsten
K
Sampson
Hugh A
HA
D000293:Adolescent; D000595:Amino Acid Sequence; D000818:Animals; D001666:Binding Sites, Antibody; D002364:Caseins / Q000737:chemistry / Q000276:immunology*; D002417:Cattle; D002648:Child; D002675:Child, Preschool; D018985:Epitopes, B-Lymphocyte; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism*; D008297:Male; D016269:Milk Hypersensitivity / Q000209:etiology*; D008969:Molecular Sequence Data
D002364:Caseins; D018985:Epitopes, B-Lymphocyte; D007073:Immunoglobulin E