Inhibition of passive cutaneous anaphylaxis by synthetic human immunoglobulin E peptide fragments

In an attempt to determine the regions responsible for type 1 immediate hypersensitivity, a total of 42 peptide fragments, which cover the CH3CH4 domains in human immunoglobulin E (IgE), were chemically synthesized. Several peptide fragments located in the amino acid sequences Ala 329—Thr 357 and Arg 119—Ala 463, inhibited passive cutaneous anaphylaxis (PCA) in vivo. In order to pinpoint the sites responsible for the inhibition of the PCA reaction, various rragment peptides in these two regions were synthesized. As a result, residues Pro 343—Leu 348, Pro 426—Thr 433, and Ser 456—Thr 401 were suggested to be involved in type I immediate hypersensitivity.