Figure 5.
(a) Comparison of absorption changes observed after 26 hours of reconstitution with: 1, retinal, 2, 9-desmethyl analogue; 3, 13-desmethyl analogue. In all cases ca. 3 µM of retinal or its analog was added to the same amount of xantho-opsin (ca. 2 µM). (b) Comparison of the kinetics of absorption changes in the carotenoid 521 nm band (assayed as a difference ΔA521–ΔA533) and the retinal band (at 600 nm), normalized at 26 h for 9-desmethyl (1 and 2, respectively) and 13-desmethyl (3 and 4, respectively).