Temperature-dependent ADMR on borohydride-treated reaction centers of Rhodobacter sphaeroides R26

✍ Scribed by V. Aust; A. Angerhofer; P.H. Parot; C.A. Violette; H.A. Frank

• Book ID: 103028224
• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 405 KB
• Volume: 173
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(90)87231-f

✦ Synopsis

Reaction centers (RC) from the carotenoid-less mutant Rhodobacter sphaeroides R26 were treated with sodium borohydride which is known to remove the M-side accessory bacteriochlorophyll molecule, BM, from the RC protein. Using absorption detected magnetic resonance (ADMR), we recorded the temperalure dependence ofthe zero-field splitting (zfs) parameters, Dand E, between 6 and 165 K. It is identical to results in native reaction centers within experimental error. The different temperature dependencies of the ADMR signal intensities in both preparations are explained by faster spin-lattice relaxation (SLR) in the radical-pair triplet state of native reaction centers.