Ammonia-Induced Structural Changes of the Oxygen-Evolving Complex in Photosystem II Diminished at 277 K as Revealed by Light-Induced FTIR Difference Spectroscopy

摘要: We have applied light-induced FTIR difference spectroscopy to study NH3-induced structural changes of the oxygen-evolving complex in photosystem II. found that spectral flash-induced spectrum PSII were gradually diminished when temperature measurement was increased from 250 277 K. Our results suggest at K, NH3 is only able bind a small fraction S2 state OEC samples containing 100 mM NH4Cl. In contrast, all result provides new interpretation for previous EPR oscillations with flash number amplitude NH3-modified multiline signal unaffected room-temperature (Boussac et al. 1990). supports NH3− binding site on gives rise modified substrate site.