Use of peptide ligands to analyze the fine specificity of antibodies against asialo GM1.
We recently described clone 10, a monoclonal Fab fragment that binds to asialo GM1 (GA1), and three mutated Abs derived from it that also bind GA1 and have a three to four times increase in avidity. We selected a phage display linear heptapeptide library with these four Abs, and an IgM mAb, 156, which binds to GM1 and GD1b, but not to GA1. Peptides with the same motif, KL/VWQXXX, were selected by clones 10 and the two heavy chain mutants 227 and 109. In contrast, the light chain mutant L3 58 selected an entirely different peptide motif, TFGLQSL. Moreover, a different motif, K/SWTNL/MPP, was selected by mAb 156. Although mAbs clone 10 and its mutants 109, 227 and L3 58 all bind only to GA1, differences in their fine specificity were revealed by binding to peptide ligands.
Qiu
J X
JX
Department of Microbiology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA.
Marcus
D M
DM
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D004797:Enzyme-Linked Immunosorbent Assay; D005677:G(M1) Ganglioside / Q000276:immunology*; D008024:Ligands; D051379:Mice; D008969:Molecular Sequence Data; D019151:Peptide Library
D000911:Antibodies, Monoclonal; D008024:Ligands; D019151:Peptide Library; D005677:G(M1) Ganglioside; C018835:asialo GM1 ganglioside