The structural influence of individual residues located within peptide antigen depends upon their sequence context

Abstract

Individual residues derived from antigenic peptides are believed to control certain mAb epitopes on MHC class I molecules. To further evaluate this influence we studied the antibody recognition of H-2Kb complexed with the antigenic peptides OVA257-264, OVA55-62 and their reciprocally substituted analogs. The mAb 20.8.4, Y-3, EH 144 and AF6 reacted strongly with Kb complexed to both OVA peptides and their analogs. However, mAb 28.8.6 bound to Kb/OVA257-264 but not Kb/OVA55-62 complexes. Recognition of Kb/OVA55-62 by mAb 28.8.6 was restored by a single OVA55-62 → OVA257-264 substitution at position 1 (OVA55-62P1K → S). Recognition by mAb 5F1 was also peptide-dependent in that Kb complexed to e..