Photochemically induced dynamic nuclear polarization in photosystem I of plants observed by 13C magic-angle spinning NMR.
Photochemically induced dynamic nuclear polarization (photo-CIDNP) has been observed in photosystem I of spinach by (13)C magic angle spinning solid-state NMR under continuous illumination with white light. An almost complete set of chemical shifts of the aromatic ring carbons of a single Chl a molecule has been obtained which is assigned to the P2-cofactor of the primary electron donor P700. Since all light-induced (13)C NMR signals appear to be emissive, a predominance of the three-spin mixing mechanism over the differential decay mechanism is proposed. The origin of the strong contribution of the three-spin mixing mechanism and the differences with photosystem II are discussed.
Contribution from the Leiden Institute of Chemistry, Gorlaeus Laboratoria, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
Alia
Esha
E
Roy
Peter
P
Gast
Hans J
HJ
van Gorkom
Huub J M
HJ
de Groot
Gunnar
G
Jeschke
Jörg
J
Matysik
D016880:Anisotropy; D002247:Carbon Isotopes; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010777:Photochemistry; D045331:Photosystem I Protein Complex / Q000737:chemistry*; D045332:Photosystem II Protein Complex / Q000737:chemistry; D011487:Protein Conformation; D018724:Spinacia oleracea / Q000737:chemistry
D002247:Carbon Isotopes; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex