Fig 8. Activity profiles of K. pneumoniae Na⁺/H⁺ exchangers.

A, Activity profile measured via SSM-based electrophysiology, under conditions of symmetrical pH (pH_in = pH_out = pH) and zero membrane potential (ΔΨ = 0). Data were taken from Fig 4. B, Activity profiles of K. pneumoniae Na⁺/H⁺ exchangers calculated using the determined kinetic parameters in Table 2 under physiological stress conditions and normalized to the transport rate determined at pH_out = 5.5. Parameters used are listed in the panel. Dashed lines in B denote pH 7 and 8.3, where the survival assays presented in Table 1 were performed. In A, out and in denote the exterior and interior of the proteoliposomes, respectively, while in B, out and in denote the periplasmic and cytoplasmic space, respectively.