Effect of modification of the chromophore in retinochrome.
14-Methyl-, 14-chloro-, 14-fluoro-retinals have been incorporated into apo-retinochrome to investigate the effect of the electronegativities of C-14 substituents on the protonation of the Schiff base. The extent of protonation decreased in going from 14-methyl- to 14-chloro- to 14-fluoro-retinal. There was usually no protonation in the case of the 14-fluoro analogue. The chromophore-protein interactions are also discussed.
Sekiya
N
N
Suntory Institute for Bioorganic Research, 1-1 Wakayamadai, Shimamotocho, Osaka 618, Japan.
Yoshihara
K
K