Picosecond dynamics of bacteriorhodopsin, probed by time-resolved infrared spectroscopy.
The photoinduced reaction cycle of bacteriorhodopsin (BR) has been studied by means of a recently developed picosecond infrared spectroscopic method at ambient temperature. BR - K difference spectra between 1560 and 1700 cm-1 have been recorded at delay times from 100 ps to 14 ns. The spectrum remains unchanged during this period. The negative difference OD band at 1660 cm-1 indicates the peptide backbone responds within 50 ps. A survey in the region of carboxylic side chain absorption around 1740 cm-1 reveals that perturbations of those groups, present in low-temperature FTIR spectra, are not observable within 10 ns, suggesting a slow conformational change.
Diller
R
R
Department of Chemistry, University of Pennsylvania, Philadelphia 19104.
Iannone
M
M
Cowen
B R
BR
Maiti
S
S
Bogomolni
R A
RA
Hochstrasser
R M
RM
D001436:Bacteriorhodopsins / Q000737:chemistry*; D006217:Halobacterium; D007700:Kinetics; D010777:Photochemistry; D013055:Spectrophotometry, Infrared
D001436:Bacteriorhodopsins