Journal Article

PreJuSER-52270

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Time-resolved microscopy on a single crystal of bacteriorhodopsin reveals lattice induced differences in the photocycle kinetics

Efremov, R.FZJ* ; Gordeliy, V. I.FZJ* ; Heberle, J. ; Büldt, G.FZJ*

2006
Rockefeller Univ. Press New York, NY

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Please use a persistent id in citations: http://hdl.handle.net/2128/716  doi:10.1529/biophysj.106.083345

Abstract: The determination of the intermediate state structures of the bacteriorhodopsin photocycle has lead to an unprecedented level of understanding of the catalytic process exerted by a membrane protein. However, the crystallographic structures of the intermediate states are only relevant if the working cycle is not impaired by the crystal lattice. Therefore, we applied visible and Fourier transform infrared spectroscopy (FTIR) microspectroscopy with microsecond time resolution to compare the photoreaction of a single bacteriorhodopsin crystal to that of bacteriorhodopsin residing in the native purple membrane. The analysis of the FTIR difference spectra of the resolved intermediate states reveals great similarity in structural changes taking place in the crystal and in PM. However, the kinetics of the photocycle are significantly altered in the three-dimensional crystal as compared to PM. Strikingly, the L state decay is accelerated in the crystal, whereas the M decay is delayed. The physical origin of this deviation and the implications for trapping of intermediate states are discussed. As a methodological advance, time-resolved step-scan FTIR spectroscopy on a single protein crystal is demonstrated for the first time which may be used in the future to gauge the functionality of other crystallized proteins with the molecular resolution of vibrational spectroscopy.

Keyword(s): Bacteriorhodopsins: chemistry (MeSH) ; Bacteriorhodopsins: radiation effects (MeSH) ; Bacteriorhodopsins: ultrastructure (MeSH) ; Crystallography: methods (MeSH) ; Dose-Response Relationship, Radiation (MeSH) ; Kinetics (MeSH) ; Light (MeSH) ; Photobiology: methods (MeSH) ; Photochemistry: methods (MeSH) ; Radiation Dosage (MeSH) ; Spectroscopy, Fourier Transform Infrared: methods (MeSH) ; Time Factors (MeSH) ; Bacteriorhodopsins ; J

Note: Record converted from VDB: 12.11.2012

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Contributing Institute(s):

1. Biologische Strukturforschung (IBI-2)

Research Program(s):

1. Funktion und Dysfunktion des Nervensystems (P33)

Appears in the scientific report 2006
Notes: This version is available at the following Publisher URL: http://www.biophysj.org/

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