15N photo-CIDNP MAS NMR analysis of reaction centers of Chloracidobacterium thermophilum
- Zill, Jeremias C. [ Institute of Analytical Chemistry, University of Leipzig, Johannisallee 29, 04103, Leipzig, Germany ]
- He, Zhihui [ Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA ]
- Tank, Marcus [ Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA ] [ Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji-shi, Tokyo, 192-0397, Japan ]
- Ferlez, Bryan H. [ Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA ]
- Canniffe, Daniel P. [ Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA ]
- Lahav, Yigal [ Fritz Haber Center of Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel ] [ Migal-Galilee Research Institute, S. Industrial Zone, 12100, Kiryat Shmona, Israel ]
- Bellstedt, Peter [ Institute of Organic and Macromolecular Chemistry, Friedrich-Schiller-Universität Jena, Humboldtstraße 10, 07743, Jena, Germany ]
- Alia, A. [ Institute of Analytical Chemistry, University of Leipzig, Johannisallee 29, 04103, Leipzig, Germany ] [ Leiden Institute of Chemistry, University of Leiden, Einsteinweg 55, P.O. Box 9502, 2300 RA, Leiden, The Netherlands ] [ Institute of Medical Physics and Biophysics, University of Leipzig, Härtelstr. 16-18, 04107, Leipzig, Germany ]
- Schapiro, Igor [ Fritz Haber Center of Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel ]
- Golbeck, John H. [ Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA ] [ Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA ]
- Bryant, Donald A. [ Montana State University: Chemistry & Biochemistry ] [ Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA ]
- Matysik, Jorg [ Institute of Analytical Chemistry, University of Leipzig, Johannisallee 29, 04103, Leipzig, Germany ]
Photochemically induced dynamic nuclear polarization (photo-CIDNP) has been observed in the homodimeric, type-1 photochemical reaction centers (RCs) of the acidobacterium, Chloracidobacterium (Cab.) thermophilum, by 15N magic-angle spinning (MAS) solid-state NMR under continuous white-light illumination. Three light-induced emissive (negative) signals are detected. In the RCs of Cab. thermophilum, three types of (bacterio)chlorophylls have previously been identified: bacteriochlorophyll a (BChl a), chlorophyll a (Chl a), and Zn-bacteriochlorophyll a' (Zn-BChl a') (Tsukatani et al. in J Biol Chem 287:5720-5732, 2012). Based upon experimental and quantum chemical 15N NMR data, we assign the observed signals to a Chl a cofactor. We exclude Zn-BChl because of its measured spectroscopic properties. We conclude that Chl a is the primary electron acceptor, which implies that the primary donor is most likely Zn-BChl a'. Chl a and 81-OH Chl a have been shown to be the primary electron acceptors in green sulfur bacteria and heliobacteria, respectively, and thus a Chl a molecule serves this role in all known homodimeric type-1 RCs.