EFFECT OF ANCHOR RESIDUE MODIFICATIONS ON THE STABILITY OF HLA-A11 PEPTIDE COMPLEXES/

MHC class I antigens bind peptides derived from endogenous proteins an d present them to cytotoxic T lymphocytes, This binding is selective a nd shows high allele specificity. Peptides binding to HLA-A11 contain a hydrophobic or a small polar amino acid at position 2 and a lysine a t the carboxy terminus. Peptide analogues, derived from previously ide ntified high affinity peptides substitutions in position 2, were used to determine the requirements for formation of stable HLA-A11/peptide complexes. By kinetic analysis we were able to discriminate among appa rent and true binders, Only analogues carrying in position 2 the amino acids valine, threonine and isoleucine formed stable complexes with H LA-A11 with a half life greater than or equal to 72 hours. (C) 1995 Ac ademic Press, Inc.