Journal of Biomolecular NMR

, Volume 54, Issue 4, pp 401–413

Characterization of the ground state dynamics of proteorhodopsin by NMR and optical spectroscopies

  • Jochen Stehle
  • Frank Scholz
  • Frank Löhr
  • Sina Reckel
  • Christian Roos
  • Michaela Blum
  • Markus Braun
  • Clemens Glaubitz
  • Volker Dötsch
  • Josef Wachtveitl
  • Harald Schwalbe
Article

DOI: 10.1007/s10858-012-9684-8

Cite this article as:
Stehle, J., Scholz, F., Löhr, F. et al. J Biomol NMR (2012) 54: 401. doi:10.1007/s10858-012-9684-8

Abstract

We characterized the dynamics of proteorhodopsin (PR), solubilized in diC7PC, a detergent micelle, by liquid-state NMR spectroscopy at T = 323 K. Insights into the dynamics of PR at different time scales could be obtained and dynamic hot spots could be identified at distinct, functionally relevant regions of the protein, including the BC loop, the EF loop, the N-terminal part of helix F and the C-terminal part of helix G. We further characterize the dependence of the photocycle on different detergents (n-Dodecyl β-D-maltoside DDM; 1,2-diheptanoyl-sn-glycero-3-phosphocholine diC7PC) by ultrafast time-resolved UV/VIS spectroscopy. While the photocycle intermediates of PR in diC7PC and DDM exhibit highly similar spectral characteristics, significant changes in the population of these intermediates are observed. In-situ NMR experiments have been applied to characterize structural changes during the photocycle. Light-induced chemical shift changes detected during the photocycle in diC7PC are very small, in line with the changes in the population of intermediates in the photocycle of proteorhodopsin in diC7PC, where the late O-intermediate populated in DDM is missing and the population is shifted towards an equilibrium of intermediates states (M, N, O) without accumulation of a single populated intermediate.

Keywords

ProteorhodopsinPhotocycleMembrane protein dynamicsNMR spectroscopy

Abbreviations

PR

Proteorhodopsin

BR

Bacteriorhodopsin

FT

Fourier transform

IR

Infrared

diC7PC

1,2-diheptanoyl-sn-glycero-3-phosphocholine

DDM

n-Dodecyl β-d-maltoside

NMR

Nuclear magnetic resonance

MES

2-(N-morpholino)ethanesulfonic acid

SRII

Sensory rhodopsin II

UV

Ultra violet

Supplementary material

10858_2012_9684_MOESM1_ESM.docx (2.4 mb)
Supplementary material 1 (DOCX 7151 kb)

Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  • Jochen Stehle
    • 1
    • 4
  • Frank Scholz
    • 3
  • Frank Löhr
    • 2
    • 4
  • Sina Reckel
    • 2
    • 4
  • Christian Roos
    • 2
    • 4
  • Michaela Blum
    • 2
    • 4
  • Markus Braun
    • 3
  • Clemens Glaubitz
    • 2
    • 4
  • Volker Dötsch
    • 2
    • 4
  • Josef Wachtveitl
    • 3
  • Harald Schwalbe
    • 1
    • 4
  1. 1.Institute for Organic Chemistry and Chemical BiologyGoethe University FrankfurtFrankfurtGermany
  2. 2.Institute of Biophysical ChemistryGoethe University FrankfurtFrankfurtGermany
  3. 3.Institute of Physical and Theoretical ChemistryGoethe University FrankfurtFrankfurtGermany
  4. 4.Center of Biomolecular Magnetic ResonanceGoethe University FrankfurtFrankfurtGermany