Related Experiment Videos
Probing the secondary quinone (QB) environment in photosynthetic bacterial reaction centers by light-induced FTIR
J Breton1, C Berthomieu, D L Thibodeau
1DBCM/SBE, C.E.N. Saclay, Gif-sur-Yvette, France.
Abstract:
The photoreduction of the secondary electron acceptor, QB, has been characterized by light-induced Fourier transform infrared difference spectroscopy of Rb. sphaeroides and Rp. viridis reaction centers. The reaction centers were supplemented with ubiquinone (UQ10 or UQ0). The QB- state was generated either by continuous illumination at very low intensity or by single flash in the presence of redox compounds which rapidly reduce the photooxidized primary electron donor P+. This approach yields spectra free from P and P+ contributions making possible the study of the microenvironment of QB and QB-. Assignments are proposed for the C...O vibration of QB- and tentatively for the C = O and C = C vibrations of QB.