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Figure 2.
Figure 2. Proton coupling and Br^− binding for wild-type and
Y445F. (a) Raw traces of CLC-ec1 currents in response to 3 s
voltage pulses (− 100 to + 100 mV in 10 mV increments) in the
presence of a four-unit pH gradient (pH[cis] 3/pH[trans] 7). (b)
I–V curves of WT (open circles) and Y445F (filled circles) in
a four-unit pH gradient. (c) Reversal potential variation with
pH (left) or Cl^− gradients (right). Reversal potentials,
V[rev], were determined for wild-type (open circles; data from
Accardi and Miller^3) or Y445F (filled circles) from I–V
curves as in (b), under varying pH or Cl^− gradients. The cis
solution, which contained 300 mM Cl^− at pH 3, was kept
constant, while the trans solution was varied. Each point
represents the average of data from at least three separate
bilayers. (e) View of the anion binding region for wild-type and
Y445F from within the membrane with the extracellular side on
top. The anomalous Br^- electron density maps (red) were
contoured at 7σ. Figure 2. Proton coupling and Br^−
binding for wild-type and Y445F. (a) Raw traces of CLC-ec1
currents in response to 3 s voltage pulses (− 100 to + 100 mV
in 10 mV increments) in the presence of a four-unit pH gradient
(pH[cis] 3/pH[trans] 7). (b) I–V curves of WT (open circles)
and Y445F (filled circles) in a four-unit pH gradient. (c)
Reversal potential variation with pH (left) or Cl^− gradients
(right). Reversal potentials, V[rev], were determined for
wild-type (open circles; data from Accardi and Miller[3]^3) or
Y445F (filled circles) from I–V curves as in (b), under
varying pH or Cl^− gradients. The cis solution, which
contained 300 mM Cl^− at pH 3, was kept constant, while the
trans solution was varied. Each point represents the average of
data from at least three separate bilayers. (e) View of the
anion binding region for wild-type and Y445F from within the
membrane with the extracellular side on top. The anomalous Br^-
electron density maps (red) were contoured at 7σ.
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