Sequence-simplified variants of a 15-mer peptide antigen, identified by amino acid side chains in alternating positions were synthesized introducing glycine residues alternatively in the parent peptide sequence and used to induce antibodies in rabbit. They reacted to a significant extent with anti-parent peptide antibodies, and in addn., affinity purified antibodies against these halved forms recognized with similar affinity and specificity, the starting peptide in affinity chromatog., optical biosensor and enzyme linked immunosorbent assay (ELISA) expts., while no cross-reactivity was detected between reduced antigens. These findings suggest that a peptide antigen can display two mol. surfaces of recognition, identified by side chains of residues in alternating positions. Each surface can even take part in antigen/antibody interaction independently, thus indicating the possibility to select and assembly sequence-simplified forms belonging to different epitopes, also deriving from different mols., to generate new structures incorporating a two-fold antigen/antibody specificity. Two "chimeric" forms were then synthesized starting from the P15 and P13 complementary peptides, both able to bind interleukin 2. These structures, showing simultaneously trans-surfaces of recognition belonging to both parent forms, have been found to retain antigenic properties against antibodies of simplified P15 derivs. showing the same mol. surface of recognition. In addn., anti-chimeric antibodies recognized both P15 and P13 starting peptides, while no cross-antibody recognition was obsd. between chimeric antigens.
Sequence-simplification and chimeric assembly: new models of peptide antigen modification
2002
Abstract
Sequence-simplified variants of a 15-mer peptide antigen, identified by amino acid side chains in alternating positions were synthesized introducing glycine residues alternatively in the parent peptide sequence and used to induce antibodies in rabbit. They reacted to a significant extent with anti-parent peptide antibodies, and in addn., affinity purified antibodies against these halved forms recognized with similar affinity and specificity, the starting peptide in affinity chromatog., optical biosensor and enzyme linked immunosorbent assay (ELISA) expts., while no cross-reactivity was detected between reduced antigens. These findings suggest that a peptide antigen can display two mol. surfaces of recognition, identified by side chains of residues in alternating positions. Each surface can even take part in antigen/antibody interaction independently, thus indicating the possibility to select and assembly sequence-simplified forms belonging to different epitopes, also deriving from different mols., to generate new structures incorporating a two-fold antigen/antibody specificity. Two "chimeric" forms were then synthesized starting from the P15 and P13 complementary peptides, both able to bind interleukin 2. These structures, showing simultaneously trans-surfaces of recognition belonging to both parent forms, have been found to retain antigenic properties against antibodies of simplified P15 derivs. showing the same mol. surface of recognition. In addn., anti-chimeric antibodies recognized both P15 and P13 starting peptides, while no cross-antibody recognition was obsd. between chimeric antigens.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
