direkt zum Inhalt springen

direkt zum Hauptnavigationsmenü

Sie sind hier

TU Berlin

Page Content

Search

Search for publications




all Publications (Reviews, Articles, Meetings and Proceedings)

Chromophore-anion interactions in halorhodopsin from Natronobacterium pharaonis probed by time-resolved resonance Raman spectroscopy
Citation key ISI:A1997XV53800027
Author Gerscher, S and Mylrajan, M and Hildebrandt, P and Baron, M H and Muller, R and Engelhard, M
Pages 11012-11020
Year 1997
ISSN 0006-2960
Address 1155 16TH ST, NW, WASHINGTON, DC 20036
Journal Biochemistry
Volume 36
Number 36
Month SEP 9
Publisher AMER CHEMICAL SOC
Abstract Halorhodopsin of Natranobacterium pharaonis which acts as a light-driven chloride pump is studied by time-resolved resonance Raman spectroscopy. In single-beam experiments, resonance Raman spectra were obtained of the parent state HR578 and the first thermal intermediate HR520. The parent state is structural heterogeneous including ca. 80\% all-trans and 20\% 13-cis isomers. The resonance Raman spectra indicate that the all-trans conformer exhibits essentially the same chromophoric structure as in the parent states of bacteriorhodopsin or halorhodopsin from Halobacterium salinarium. Special emphasis of the resonance Raman spectroscopic analysis was laid on the C=C and C=N stretching region in order to probe the interactions between the protonated Schiff base and various bound anions (chloride, bromide, iodide). These investigations were paralleled by spectroscopic studies of retinal Schiff base model complexes in different solvents in an attempt to determine the various parameters which control the C=C and C=N stretching frequencies, From these data, it was concluded that in the parent state the anion is not involved in hydrogen bonding interactions with the Schiff base proton but is presumably bound to a nearby (positively charged) amino acid residue, On the other hand, the anion still exerts an appreciable effect on the chromophore structure which is, for instance, reflected by the variation of the isomer composition in the presence of different anions and in the anion-depleted form. In contrast to the parent state, the intermediate HR520 reveals frequency shifts of the C=N stretching in the presence of different anions. These findings indicate a closer proximity of the bound anion to the Schiff base proton which is sufficient for hydrogen bonding interactions. These changes of the anion-chromophore interaction upon transition from HR578 to HR520 may be related to the coupling of the chromophore movement with the anion translocation.
Bibtex Type of Publication Article
Download Bibtex entry

Zusatzinformationen / Extras

Quick Access:

Schnellnavigation zur Seite über Nummerneingabe

This site uses Matomo for anonymized webanalysis. Visit Data Privacy for more information and opt-out options.