Abstract
In Cyanobacterial Photosystem II, Electron Electron Double resonance for the radical pair of carotenoide and YD were observed when the sample was illuminated at 77 K. The observed frequency is about 3 MHz corresponding average distance between both radical to be 29 A. Carotenoide has a long chain with its spin densities extending over both molecular edges. On the other hand, YD with 6 member carbon ring in PSII has been well studied, and structural data have been derived from X-ray analysis. To analyze the ELDOR spectra using these structural(1) data of YD and electronic data of carotenoide and assuming orientation, simulation will predict the orientation of carotenoide molecule. Two carotenoide molecules have been investigated, The other is situated close to YZ molecule. To determine the active carotenoide we are going to pursuit ELDOR for the YZ trapped sample.
1. B.Loll et al. Nature 438(2005) 1038-1044
2. T. A. Konovalo et al. J. Phys. Chem. B2001 105 8361-8368
