FIGURE 6.
Kinetics of the bleaching process in K296G/nPrSB and wild-type rhodopsin. a and b, effect of the high affinity C-terminal peptide of Gtα on the formation of Meta-II (CHAPS/PC purified pigments, 273 K, pH 7.6, 50 μm high affinity peptides). The difference spectra of pigments immediately after and 72 min after light excitation, without (black lines) and with (gray lines) high affinity peptides. c and d, time course of the absorbances at 380, 465, and 500 nm. The wild type exhibits a classic behavior, producing more Meta-II in the presence of high affinity peptides. On the other hand, the spectra and the kinetics of K296G/nPrSB are completely unaffected by the high affinity peptides.