Figure 2.
A panel of peptides bearing aldehyde functional groups was synthesized based upon the DQ2-αI (1) and DQ2-αII (7) gluten peptides. Substitutions were made at both the P4 and P6 HLA-DQ2 binding positions of the peptides. Further, the side-chain length was varied to find the binding optimum. Based upon the binding results of peptides 1−11, putatively optimal aldehyde substitutions were made in the 20mer gluten peptide (12). All peptides are labeled at the N-terminus with the fluorophore 5(6)-carboxyfluorescein (designated f).