Time-resolved protein fluorescence studies of intermediates in the photochemical cycle of bacteriorhodopsin.
- 1 January 1981
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 78 (1) , 252-255
- https://doi.org/10.1073/pnas.78.1.252
Abstract
The photolysis-induced changes in the protein fluorescence intensity (at 320 nm) during the proton-pumping cycle of bacteriorhodopsin were examined by a delayed 2-pulse technique in the time range 1 .mu.s-20 ms at room temperature. No detectable change in the protein fluorescence intensity was observed on the earliest time scale within the lifetime of the intermediate K590, when retinal apparently undergoes the largest structural changes. The time dependence of the relative changes in fluoresence intensity did display a close correlation with the population of the L550 and M412 intermediates. From a computer numerical fit of the data, with available published kinetic parameters, the protein fluorescence quantum yields of the K590, L550 and M412 intermediates are found to be 1.0, 0.92 and 0.80 of that for native bR570, respectively. The probable mechanisms of the observed fluorescence quenching during the photochemical cycle are qualitatively discussed.This publication has 27 references indexed in Scilit:
- Kinetic interaction between aromatic residues and the retinal chromophore of bacteriorhodopsin during the photocycleFEBS Letters, 1979
- Bacteriorhodopsin and the purple membrane of halobacteriaBiochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics, 1979
- Tyrosinate fluorescence maxima at 345 nm in proteins lacking tryptophan at pH 7FEBS Letters, 1978
- Primary intermediates in the photochemical cycle of bacteriorhodopsinBiophysical Journal, 1978
- Light-dark conformational states in bacteriorhodopsinBiochemical and Biophysical Research Communications, 1976
- Bicycle-pedal model for the first step in the vision processNature, 1976
- Improved Isolation Procedures for the Purple Membrane of Halobacterium HalobiumPreparative Biochemistry, 1975
- Light‐dependent reaction of bacteriorhodopsin with hydroxylamine in cell suspensions of Halobacterium halobium: Demonstration of an APO‐membraneFEBS Letters, 1974
- FLUORESCENCE AND THE LOCATION OF TRYPTOPHAN RESIDUES IN PROTEIN MOLECULESPhotochemistry and Photobiology, 1973
- Reversible Photolysis of the Purple Complex in the Purple Membrane of Halobacterium halobiumEuropean Journal of Biochemistry, 1973