TY - JOUR
T1 - The field-dependence of the solid-state photo-CIDNP effect in two states of heliobacterial reaction centers
AU - Surendran Thamarath, Smitha
AU - Alia, A.
AU - Roy, Esha
AU - Sai Sankar Gupta, Karthick Babu
AU - Golbeck, John H.
AU - Matysik, Jörg
N1 - Funding Information:
Acknowledgments The authors thank to A.H.M de Wit for helping in culturing the bacteria. Helpful discussions with Prof. G. Jeschke and G.J. Janssen are acknowledged. F. Lefeber, K. Erkelens and Bryan Ferlez are gratefully acknowledged. Generous financial support of NWO (818.02.019, 713.012.001) is acknowledged. JHG is supported by the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy, via Grant DE-FG02-08ER15989.
PY - 2013/11
Y1 - 2013/11
N2 - The solid-state photo-CIDNP (photochemically induced dynamic nuclear polarization) effect is studied in photosynthetic reaction centers of Heliobacillus mobilis at different magnetic fields by 13C MAS (magic-angle spinning) NMR spectroscopy. Two active states of heliobacterial reaction centers are probed: an anaerobic preparation of heliochromatophores ("Braunstoff", German for "brown substance") as well as a preparation of cells after exposure to oxygen ("Grünstoff", "green substance"). Braunstoff shows significant increase of enhanced absorptive (positive) signals toward lower magnetic fields, which is interpreted in terms of an enhanced differential relaxation (DR) mechanism. In Grünstoff, the signals remain emissive (negative) at two fields, confirming that the influence of the DR mechanism is comparably low.
AB - The solid-state photo-CIDNP (photochemically induced dynamic nuclear polarization) effect is studied in photosynthetic reaction centers of Heliobacillus mobilis at different magnetic fields by 13C MAS (magic-angle spinning) NMR spectroscopy. Two active states of heliobacterial reaction centers are probed: an anaerobic preparation of heliochromatophores ("Braunstoff", German for "brown substance") as well as a preparation of cells after exposure to oxygen ("Grünstoff", "green substance"). Braunstoff shows significant increase of enhanced absorptive (positive) signals toward lower magnetic fields, which is interpreted in terms of an enhanced differential relaxation (DR) mechanism. In Grünstoff, the signals remain emissive (negative) at two fields, confirming that the influence of the DR mechanism is comparably low.
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U2 - 10.1007/s11120-013-9854-x
DO - 10.1007/s11120-013-9854-x
M3 - Article
C2 - 23722589
AN - SCOPUS:84888881949
SN - 0166-8595
VL - 117
SP - 461
EP - 469
JO - Photosynthesis research
JF - Photosynthesis research
IS - 1-3
ER -