Analysis of IgE reactivity to GST fusion peptides and synthetic peptides.

<p>A, The data shown represent the results for patient 10. Immunoblots of purified GST fusion peptides Pen c 13 (A<sup>243</sup>–K<sup>274</sup>), (A<sup>243</sup>–A<sup>260</sup>) and (T<sup>261</sup>–K<sup>274</sup>); GST fusion Pen c 13 (T<sup>261</sup>–K<sup>274</sup>) mutant peptides S269A, G270A, T271A, T272A, S273A or K274A; and GST only, probed with serum from a Pen c 13-allergic patient. The protein blots were stained with Fast Green as a loading control. B, The histogram shows the quantitative densitometry of the bands. C, The critical amino acid for IgE-binding in Pen c 13 (T<sup>261</sup>–K<sup>274</sup>) was validated further using two synthetic peptides and tested for IgE-binding reactivity with pool serum from 10 allergic patients. The sequences of two synthetic peptides are listed, and the residue that was changed to alanine is <i>underlined</i>. Alanine substitution is shown in <i>boldface letter</i>.</p>