<p><a></a><a></a><a>We have validated
that ligand peptides designed from antigen peptides could be used for targeting
specific major histocompatibility complex class I (MHC-I)</a> molecules on
cell surface. To design the ligand peptides, we used reported antigen peptides for
each MHC-I molecule with high binding affinity. From the crystal structure of
the peptide/MHC-I complexes, we determined a modifiable residue in the antigen
peptides and replaced this residue with a lysine with an ε-amine group modified with functional molecules. The
designed ligand peptides successfully bound to cells expressing the
corresponding MHC-I molecules via exchange of peptides bound to the MHC-I. We
demonstrated that the peptide ligands could be used to transport a protein or a
liposome to cells expressing the corresponding MHC-I. The present strategy may
be useful for targeted delivery to cells overexpressing MHC-I, which have been
observed autoimmune diseases.</p>
