Electric-field effects in 13-demethyl-11,14-epoxyretinal-bacteriorhodopsin films
01 July 1999
We report the results of experiments on the application of electric fields across thin, dry films of a bacteriorhodopsin (BR) analog pigment in which the retinal chromophore has been replaced with 13-demethyl-11,14-epoxyretinal. As previously observed in other BR variants with low Schiff-base pK values, this pigment exhibits protonation and deprotonation of the Schiff base under an applied electric field, depending on the initial Schiff-base protonation state or effective pH. At low effective pH, a fast (