Fig. 7. Observed changes
in the selectivity (reversal potential) in yeast VDAC channels following
single site-directed mutations. The reversal potentials were divided
by the magnitude and sign of the charge change
at the site produced by the amino-acid substitution. They are plotted against
the position of the residue from the N
terminus. The reversal potentials are compilations
of previously-published data (Blachly-Dyson et al, 1990; Peng et al., 1992a).
The were collected on single
channels after reconstitution into a planar membrane
(as in Fig. 1) in the presence of a 10 fold KCl
gradient. Positive values indicate that the selectivity change was in
the direction expected from the charge change.
Solid bars represent significant changes in selectivity.