Abstract
Most Chl a in the PS1RC complexes was removed by ether treatment without any loss of P700, yielding the antenna-depleted complexes with a Chl a/P700 ratio of 13. (1) Chl b, Chl a-epimer or Chl d, which have a side chain different from Chl a, could bind to the Chl a-binding sites of the antenna-depleted PSIRC complexes and transfer its excitation energy to P700 with an efficiency as high as Chl a, except Chl d, of which excited-state level is almost equal to that of P700. (2) Metal-substituted Chl a could bind to the Chl a-binding sites; the excitation-energy could be transferred to P700 with Zn-, Cd- or Sn-Chl a, but not with Hg-, Cu- or Fe-Chl a, possibly depending on the lifetime of their excited states. (3) Zn-Chlorophyllide a lacking phytol, could bind twice more efficiently to the complexes, but with less excitation-energy transfer than Zn-Chl a.
