Table 1.

Kinetic parameters of the transient currents measured for wild-type LacY

pHEfflux, %Peak current, %τ1/2, msK0.5, mM
8.510010027 ± 0.66.9 ± 0.7
7.6355546 ± 25.3 ± 0.5
6.6619103 ± 74.3 ± 0.8
  • For comparison the effect of pH on the initial rates of [14C]lactose efflux is given (22). The peak currents and the time constants (τ1/2) refer to the transient currents after 50 mM lactose concentration jumps. Conditions are as described in Fig. 3.