English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Quantum efficiency of native and mutant bacteriorhodopsin obtained from blue light induced relaxation experiments

MPS-Authors
/persons/resource/persons47688

Butt,  Hans-Jürgen
Transport Proteins Group, Max Planck Institute of Biophysics, Max Planck Society;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Butt, H.-J. (1990). Quantum efficiency of native and mutant bacteriorhodopsin obtained from blue light induced relaxation experiments. European Biophysics Journal, 19, 31-39. doi:10.1007/BF00223571.


Cite as: http://hdl.handle.net/21.11116/0000-0007-A7BA-B
Abstract
Bacteriorhodopsin was continuously excited with green background light. In this way a steady state distribution of all intermediates of the photocycle was obtained. Then a perturbation of the system was induced by a blue laser flash and the resulting absorption changes were measured. The experiments were done with native bacteriorhodopsin and with the point mutant BR Asp96→Asn, in which aspartate 96 is changed to asparagine. Blue light induced relaxation experiments revealed a rate constant belonging to the excitation of bacteriorhodopsin by the green background. With this rate constant the quantum efficiency of native bacteriorhodopsin and of BR Asp96→Asn was determined to be 0.60 ± 0.10. Signals obtained with native bacteriorhodopsin could be explained with a simple model of the photocycle consisting of three consecutive intermediates BR 568, L 550 and M 412. To describe the behavior of BR Asp96→Asn , a further photoactive intermediate after the M 412 state had to be postulated. Properties of this intermediate are similar to those of the N 550 state.