Photoinduced transformation of 14-F-bacteriorhodopsin gelatin films based on both wild type and D96N mutant

Spectral and kinetic transformations were studied in gelatin films made wit h 14-F wild type (WT) bacteriorhodopsin (BR) and 14-F D96N mutant BR. Unlik e the recent study of watts suspensions of the same pigments, where a red s hifted species at 660 nm was shown to form under the light in 14-F WT only. there are no drastic differences in photoinduced behavior between gelatin films based on 14-F WT and 14-F D96N. It is not observed any photoinduced f ormation of red shifted species at 660 nm for both types, of films as it is observed for corresponding pigments in water suspension. The observed resu lts are explained in a terms of relationship between the rates of two photo induced processes that occur in suspensions and films of corresponding pigm ents. Kinetic characteristics of the photoinduced processes for the Elf ms with chemical additives suggest that there are no advantages in using 14-F D96N films when compared to films based on 14-F WT. (C) 2001 Elsevier Scien ce Ireland Ltd. All rights reserved.