Figure 3.

Identification of an antigenic peptide recognized by C18. (A) Serial 9-mer synthetic peptides were synthesized incorporating the position 136 amino acid in the mutated (1m to 9m) or nonmutated (8wt and 9wt) ERK2 product. (B) Two peptides, 8m and 9m, sensitized DBA/2 (H-2^d)-derived P1. HTR target cells equally well against C18 lysis at concentrations of 1 nM and 10 nM. (C) The 9m peptide was more efficient in sensitizing P1. HTR target to C18 lysis than other peptides. (D) The affinity of peptides 9m and 9wt for K^d was measured in a binding-inhibition assay using a K^d-restricted human erbB2 peptide. Peptides 9m and 9wt had comparable K^d binding affinity, whereas the 3m peptide had no inhibitory activity.