Determination of amino acids on agretopes of pigeon cytochrome c-related peptides specifically bound to I-A allelic products

摘要: In our prior study it was demonstrated that residues 46 and 54 on a synthetic peptide, AEGFSYTVANKNKGIT (50V), work as an agretope (site contacts with major histocompatibility complex molecules) 50 52 function epitope T cell receptor), when tri-molecular complexes are formed among 50V, I-Ab the receptor. 50V composed of 43 to 58 pigeon cytochrome c (p43--58) except aspartic acid (D) at residue substituted by valine (V). Substitution agretopic changed this I-Ab-binding peptide I-Ak-binding suggesting positions in I-Ak-restricted responses. present we examined whether worked agretopes responses restricted other I-A haplotypes. The 50V-related peptides phenylalanine (F) position alanine (A) bound tightly I-Ab, I-Ad, I-Aq I-As molecules stimulated cells most potently mice bearing these contrast, carrying D A I-Ak molecules, arginine (R) efficiently I-Av molecules. findings, thus, demonstrate p43--58 related preserved each haplotype studied, specific amino acids exist priori for allele-specific structure.