FIGURE 3.

Effect of ficoll applied to the periplasmic side of MscS on the channel currents. (A) Ficoll changed reversibly the time constant of inactivation, τ, inactivation was slower, and the number of activated channels was unaffected. Addition of ficoll to the cytoplasmic side of the channel accelerated inactivation. All traces were recorded from the same patch at +15 mV. Suction pulse (indicated by the downward arrow) was 232 mm Hg and its duration was 12 s. c marks the closed level of the channels. (B) Change of the inactivation time constant, τ, as a function of pressure in the experiment shown in A.