“Empty” rDQ2.5 (RTL800) was derived from DQ2 (DQA1*0501/DQB1*0201), RTL302 from DR2 (DRA1*0101/DRB1*1501), and RTL600 from DP2 (DPA1*0103/DPB1*0201) primary sequences. Gaps in the sequences for optimal alignment (*) and the beta-1//alpha-1 junction (←|→) are shown. The conserved cysteines that form a disulfide bond are shaded yellow, and the cysteine residue present in DQ2-derived RTL800 that has been changed to Serine in RTL801 to prevent intermolecular disulfide bond formation and aggregation is underlined. Genes encoding RTL802 & RTL803, variants of 800 and 801, respectively, encode proteins that have the amino-terminal peptide sequence (MFPQPELPYPQPGSGSGSGSGSGSGSGS) instead of the starting methionine. These molecules bear antigenic α2-gliadin-61-71 (Q65E) “α-II” peptide and linker (the gliadin-derived sequence is underlined).