Background:

H-Lys-Ala-Glu-Arg-Ala-Asp-Leu-Ile-Ala-Tyr-Leu-Lys-Gln-Ala-Thr-Ala-Lys-OH
The I-Ek-restricted T cell response to Cytochrome c - pigeon (pcyt c) is specific for a peptide within the COOH-terminal sequence 88-1041.
The minimal length of the pcyt c peptide required for T cell stimulation is the COOH-terminal sequence containing residues 95-104. However, the addition of residues to the NH2 terminus of residue 95 increases the antigenic potency of the peptide; the maximal response is induced by pcyt c 88-1042.
The substitution of any residue between 95 and 104 of the cytochrome c peptide changed the antigenic potency of the peptide for at least one of the hybridomas3.

参考文献:
1. Schwartz, R. H. 1985. T lymphocyte recognition of antigen in association with gene products of the MHC. Annu. Rev. Immunol. 3:237.
2. Bhayani, H., F. R. Carbone, and Y. Paterson. 1988. The activation of pigeon cytochrome c-specific T cell hybridomas by antigenic peptides is influenced by non-native sequences at the amino terminus of the determinant. J. Immunol. 141:377.
3. Bhayani, H., Y. Paterson. 1989. Analysis of peptide binding patterns in different major histocompatibility complex/t cell receptor complexes using pigeon cytochrome c-specific t cell hybridomas.