Figure 6. Comparison of PDS labeling rate among cysteine mutants and relationship analysis of PDS labeling rate with Meta II decay.
A) Rates of cysteine reactivity with 4-PDS were evaluated in mutants (F115/, F116/, A117/, T118/, V130/, L131/, A132/, I133/, and R135/Basal mutant). The reaction was carried out with 0.5 µM of rhodopsin mutant and 25 µM 4-PDS in phosphate buffer (pH8.0) and 0.05% DM at 20°C. Time-dependent changes in absorbance at 323 nm after photoactivation were plotted. B) Rates of cysteine reactivity with 4-PDS (dark gray) and Meta II decay (light gray) in relationship to the amino acid position.