FIGURE 1.

Ionic currents evoked by step changes in pH for HEK 293 cells expressing GLIC and mutants of the three intrinsic His residues. A, crystal structure of GLIC (7) (PDB code 3EAM) with the three His residues shown in space-filling representation. B, ionic currents versus time evoked by the indicated step changes in pH for mock-transfected cells, wild type GLIC, and the indicated His mutants. Currents with fast response shown in mock-transfected cells are from endogenous pH-sensitive channels.