Figure 8.

Blue shift of rhodopsin mutant photointermediates relative to rhodopsin’s λ_max (498 nm). The blue shift of the λ_max values of rhodopsin’s photointermediate are indicated by “wt” in the plot, and since Meta I₄₈₀ does not appear to any significant degree in DM suspensions of rhodopsin, the value of its blue shift obtained in membrane suspensions is denoted here as “wt”. Where no Lumi I - Lumi II transition was detected (E122Q, E134R/R135E and E134Q), only the undifferentiated Lumi photointermediate’s blue shift is plotted. Changes in the size of the labels denotes changes in the plotted photointermediate’s extinction coefficient. Notable here is that mutation of either Glu122 or His211 produces a large blue shift of the Lumi intermediate which persists in Meta I₄₈₀.