Evidence for antibody activity against the receptor for IgE in a rabbit antiserum prepared against IgE-receptor complexes
Conrad, D.H.; Froese, A.; Ishizaka, T.; Ishizaka, K.
Journal of Immunology 120(2): 507-512
1978
ISSN/ISBN: 0022-1767 PMID: 621390 Document Number: 136528
A rabbit antiserum prepared against rat Ig polyacrylamide gels. The major component bound by the antibodies had a relative mobility identical to that of the receptor for IgE. Confirmation that this component was indeed the receptor for IgE was shown in that this receptor was progressively removed from the NP-40 extract by increasing amounts of the purified antibodies. The ability of these purified antibodies to interact with the receptor was strongly inhibited when the receptor was complexed with IgE; the purified antibodies demonstrated little activity against purified IgE-receptor complexes. The antigenic site(s) interacting with the purified antibodies were either in or closely adjacent to the IgE-binding site on the receptor. The original antiserum, after removal of anti-IgE antibodies by absorption with IgE covalently linked to Sepharose, demonstrated significant activity against the purified IgE-receptor complexes. Antibodies against sites on the receptor distant from the IgE-combining site may be present in the original antiserum. These sites were probably buried in the membrane and thus lost in the antibody purification procedure.