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.
Alia
Contribution from the Leiden Institute of Chemistry, Gorlaeus Laboratoria, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
Roy
Esha
E
Gast
Peter
P
van Gorkom
Hans J
HJ
de Groot
Huub J M
HJ
Jeschke
Gunnar
G
Matysik
Jörg
J
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