Carbonera D, Giacometti G, Agostini G
Department of Physical Chemistry, University of Padua, Italy.
FEBS Lett. 1994 May 2;343(3):200-4. doi: 10.1016/0014-5793(94)80555-5.
An ADMR T-S spectrum of the primary donor (P680) of photosystem II (PSII) was obtained from anaerobically photoreduced particles. The spectrum is the best resolved obtained so far having a main bleaching band at 684 nm with a linewidth of only 100 cm-1. The view that this spectrum is produced by native homogeneous P680 unlike those obtained before is defended. A small bleaching observed at 678 nm is discussed in terms of the reaction center structure. One possible interpretation of the observations is that P680 is a very loose dimer with an exciton splitting of only 144 cm-1 corresponding to a dimer center-to-center distance of roughly 11.5 A.
