The effect of hydration on protein flexibility in photosystem II of green plants studied by quasielastic neutron scattering.
The effect of hydration on protein dynamics in photosystem II (PS II) membrane fragments from spinach has been investigated by using the method of quasielastic neutron scattering (QENS) at room temperature. The QENS data obtained indicate that the protein dynamics is strongly dependent on the extent of hydration. In particular, the hydration-induced activation of localized diffusive protein motions and QA- reoxidation by QB in PS II appear to be correlated in their onset at a hydration value of about 45% relative humidity (r.h.). These findings underline the crucial functional relevance of localized diffusive protein motions on the picosecond-timescale for the reactions of light-induced photosynthetic water splitting under formation of plastoquinol and molecular oxygen in PS II of green plants.
Pieper
J
J
Max-Volmer-Laboratories for Biophysical Chemistry, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany, joerg.pieper@tu-berlin.de
Hauss
T
T
Buchsteiner
A
A
Renger
G
G
D017666:Deuterium Oxide / Q000494:pharmacology; D004579:Electron Transport; D033363:Neutron Diffraction; D055095:Optics and Photonics; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D018724:Spinacia oleracea / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature; D014867:Water / Q000494:pharmacology*
D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D014867:Water; D017666:Deuterium Oxide