Fig. 3. Chromophore states and channel currents.
Chromophore configurations in RSB: all-trans, 15-anti (trans, anti) of dark-adapted state; 13-cis, 15-syn (cis, syn) of second dark state (increasingly occupied after blue illumination during photocurrent inactivation from initial I0 to stationary IS; inset) (1, 37). In corresponding open states occupied after 13C=14C photoisomerization, RSB is in the 13-cis, 15-anti (cis, syn) configuration in the open conducting state O1 and 13-trans, 15-syn (trans, syn) in O2 (1, 37). Cis-trans isomerization is indicated by red arrows, anti-syn isomerization by blue arrows, photochemical conversions by green arrows, and thermal conversions by black arrows.