FIGURE 3.

Effect of 11-cis-retinol and -retinal on opsin activation and pigment regeneration in salamander blue cones and green rods. A, transducin activation by expressed salamander blue cone/green rod opsin (open circles) with 11-cis-retinol (filled circles) and 11-cis-retinal (triangles). Each sample was assayed in triplicate and averaged; error bars reflect mean ± S.E. and often were smaller than the symbol size. At 5.5 min, samples with 11-cis-retinal and 11-cis-retinol were illuminated with light for 12 s as described under “Experimental Procedures” and illustrated in the figure with the vertical line. B, averaged spectra of single salamander blue cones: dark adapted (gray circles, n = 8), 1–9 min after >90% bleach (open circles, n = 13), and 60 min following exposure to 11-cis-retinol applied 85 min following the bleach (black filled circles, n = 7). Inset, normalized absorption spectra of salamander blue cones before and after bleaching and regeneration with 11-cis-retinol (circles, n = 7) or 11-cis-retinal (triangles, n = 5). C, spectra of a single dark-adapted salamander green rod before bleaching (gray circles), after bleaching measured at 2 (black dashes) and 32 min (open circles), and after treatment with 11-cis-retinol in vesicles for 90 min (black filled circles).