Primary events in bacteriorhodopsin probed by subpicosecond spectroscopy

• Published in: Biochimica et biophysica acta, Protein structure and molecular enzymology Vol. 808; no. 1; pp. 94 - 102
• Main Authors: Sharkov, A V, Pakulev, A V, Chekalin, S V, Matveetz, YA
• Format: Journal Article
• Language: English
• Published: 01.01.1985
• ISSN: 0167-4838

The photochemical cycle of light-adapted bacteriorhodopsin at room teperature was initiated by 0.6-ps single pulses at 615 nm. In the spectral region from 410 to 750 nm the absorption difference spectra were measured. Three photoinduced states have been observed during the first 10 ps after excitation. The difference spectrum between the latest one and bacteriorhodopsin is similar to the difference spectrum between the earlier observed K intermediate (with nanosecond lifetime) and bacteriorhodopsin. The K intermediate is preceded by the primary photoproduct with 3-ps lifetime (the J intermediate). Both J and K have red-shifted spectra compared with the initial spectrum of bacteriorhodopsin. The earliest state has a lifetime of 0.7 ps, and a blue-shifted spectrum.