Basic residues were mutated to alanine in silico using Pymol (DeLano Scientific), and the surface potential of the mutated TCRs were calculated using the APBS plugin in Pymol. The TCRs are oriented with the γ chains on the top left and the δ chains on the bottom right of the panels. Top down views of the surface potential of the Vγ2Vδ2 TCR are shown (colored from red (−8 kT) to blue (+8 kT). The two positively charged regions are circled. A, Surface potential for the unmutated Vγ2Vδ2 TCR. B–F, Effect on surface potential of alanine replacement of R59A and K60Aγ (B), R51Aδ (C), K109Aγ (D), K108Aγ (E), and K111Aγ (F).