Triplet EPR spectra of the primary electron donor in bacterial photosynthesis at temperatures between 15 and 296 K

✍ Scribed by A.J. Hoff; I.I. Proskuryakov

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 760 KB
• Volume: 115
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(85)80033-6

✦ Synopsis

Spm polarized tnplet EPR spectra of reaction centers of the photosyntheuc bacterium Rhodopseudomonas sphoerordes 2.4 1 and its carotenoidkss mutant R-26 have been measured from 15 to 296 K with direct detecuon flash-EPR For the mutanS the zero-field parameter IDI increases appreciably wth temperature makmg It unhkely that at higher temperatures a donor-acceptor charge-transfer state is muted in the tnplet state of the primary electron donor, 3D g-values along the canomcal field clirectmns have been measured, and spm-lattice relaxation donunatcs over mokcular decay at temperatures B 133 K For the anld type. the wmperature dependence of the rate of tnplet transfer from 'D to reactmn center carotenold has been measured, and it is shown that the difficulty m observing 3Car above 200 K is due to fast spm-latuce relaxation.