Nanosecond-Flash N-15 Photo-CIDNP MAS NMR on Reaction Centers of Rhodobacter sphaeroides R26

作者：Daviso Eugenio; Prakash Shipra; Alia A; Gast Peter; Jeschke Gunnar; Matysik Joerg^*

来源：Applied Magnetic Resonance, 2010, 37(1-4): 49-63.

DOI：10.1007/s00723-009-0050-2

Photochemically induced dynamic nuclear polarization (photo-CIDNP) is observed with time-resolved N-15 magic-angle spinning (MAS) nuclear magnetic resonance (NMR) in uniformly N-15-labeled reaction centers (RCs) of the purple bacterium Rhodobacter (Rb.) sphaeroides R26 under illumination with nanosecond laser flashes. The N-15 NMR signals enhanced by the solid-state photo-CIDNP effect are related to electron spin densities in the primary radical pair and allow for reconstruction of the electronic structure at atomic scale. New assignments for the photochemically active nitrogens are proposed based on simulations of the intensities. The ratio of electron spin densities between cofactors P (L) and P (M) is observed to be about 4:1. The origin of the high asymmetry is discussed.

• 出版日期2010-1