Voltage-Dependent Inactivation of MscS Occurs Independently of the Positively Charged Residues in the Transmembrane Domain

Figure 4

Rate of inactivation in the wild-type and mutant MscS expressed in MJF455 (ΔmscSΔmscL) cells. (a) Macroscopic currents of wild-type (upper) and R46N MscS (bottom). Voltage was changed from −20 to +60 mV (upper middle) in the presence of pressure (lower middle). Red traces show the traces at the pressure where MscS was activated fully (−183 mmHg in wild-type and −203 mmHg in R46N MscS). (b) Time constant of fast and slow components of the wild-type and mutant MscS (mean ± SE, –7) as determined by fitting current traces to two-exponential functions.

(a)

(b)