Determination of antigenic peptide selection by heterozygote APC containing I-A ^g7 - I-A ^X

The determination of peptide extract taken from l-A ^g7 cell line was discussed. The peptides were extracted from l-A ^g7 and other structurally similar MHC (l-A ^g7pd and l-A ^d) and peptide repertoire of homozygotic cell lines were compared to that of heterozygotic cell lines. A large number of peptides were analyzed using tendem MS. 25 peptide sequences were determined using MASCOT as the database search program, by using reverse phase-nano-LC and the LCQ-deca. The results show that most of the peptides selected by l-A ^g7 are unusually rich in acidic residues toward their C-termini.