Preparation of high-quality full-length ZnT8 antigens. (A) Purified full-length ZnT8 in detergent micelles (DS-ZnT8) or proteoliposomes (PLR-ZnT8) shown by Coomassie blue staining of a SDS/PAGE gel. Magenta, red, and dark-brown arrows indicate full-length ZnT8 dimer, monomer, and lipids, respectively. (B) Schematic of transmembrane orientations of full-length ZnT8 in reconstituted proteoliposomes as marked. Double-layer circles, cyan ribbons, magenta spheres, and green or blue autoantibodies represent liposomes, full-length ZnT8, zinc ions, and ZnT8A binding to the extracellular or intracellular surface of full-length ZnT8, respectively. (C) Size-exclusion HPLC profiles of PLR-ZnT8 before (red) and after (blue) vacuum drying (Left) and of DS-ZnT8 before (red) and after (blue) vacuum drying (Right). Magenta and black arrows indicate full-length ZnT8 and lipids, respectively. (D) DLS analysis of ZnT8-free liposomes and PLR-ZnT8. The size of liposomes increased from ∼104 to ∼146 nm after reconstitution of full-length ZnT8.