Figure 3:

Results of molecular docking. Panels A and B: HLA-B*14:01 exhibited an unpaired cysteine at position 67 with the potential to bind reactive SMX metabolite sulfonamide. The molecular surface of a model of HLA-B*14:01 is shown in light blue. Sulfonamide is shown as sticks, white for carbon, blue for nitrogen, red for oxygen. Cys⁶⁷, Trp⁹⁷, and Thr¹⁶³ are shown in red. Panels C and D: Molecular docking predicted interaction between SMX and the antigen binding cleft of HLA-B*35:01. The crystal structure of HLA-B*35:01 is shown (PDB code 6BJ8), colored based on sequence similarity to HLA-B*15:02. Blosum62 similarity values are: blue, 40–50, cyan, 50–60, green, 60–70, yellow, 70–80, orange 80–90, and red 90–100. Molecular docking (AutoDock Vina, ΔG=−7.6 kcal/mol) predicted SMX interaction with residues shared by HLA-B*35:01 and HLA-B*15:02 shown as sticks. Predicted H bond interactions are shown as black dashed lines. The position 67 (Phe⁶⁷), which we detected in our AA analysis, was not predicted to form contact with SMX by molecular docking.