Molecular Mechanism of the Differential Photoelectric Response of Bacteriorhodopsin

TitleMolecular Mechanism of the Differential Photoelectric Response of Bacteriorhodopsin
Publication TypeJournal Article
Year of Publication1997
AuthorsWang, J, Yoo, S-K, Song, L, EL-Sayed, MA
JournalThe Journal of Physical Chemistry B
Volume101
Issue17
Pagination3420 - 3423
Date Published1997
ISBN Number1520-6106
Abstract

In order to determine the molecular origin of the differential photocurrent from bacteriorhodopsin (bR), the photoelectric response of bR film deposited on an indium tin oxide (ITO) conductive glass electrode under CW excitation is compared with that under pulsed laser excitation at different pH and with opposite membrane orientation with respect to the ITO electrode surface. The characteristics (sign and magnitude) of the dominant component of the differential photocurrent (appearing on the millisecond time scale) are found to correlate with the process of proton release into, or uptake from, the aqueous solution during the photocycle under different experimental conditions. This suggests that the differential current results mainly from the change in the H+ concentration at the bR?ITO electrode interface.In order to determine the molecular origin of the differential photocurrent from bacteriorhodopsin (bR), the photoelectric response of bR film deposited on an indium tin oxide (ITO) conductive glass electrode under CW excitation is compared with that under pulsed laser excitation at different pH and with opposite membrane orientation with respect to the ITO electrode surface. The characteristics (sign and magnitude) of the dominant component of the differential photocurrent (appearing on the millisecond time scale) are found to correlate with the process of proton release into, or uptake from, the aqueous solution during the photocycle under different experimental conditions. This suggests that the differential current results mainly from the change in the H+ concentration at the bR?ITO electrode interface.

URLhttp://dx.doi.org/10.1021/jp962111j
Short TitleJ. Phys. Chem. B