A 3-D Structural Model of Solid Self-Assembled Chlorophyll a/H2O from Multispin Labeling and MAS NMR 2-D Dipolar Correlation Spectroscopy in High Magnetic Field

2D13C–13C MAS NMR Correlation Spectroscopy with Mixing by True 1H Spin Diffusion Reveals Long-Range Intermolecular Distance Restraints in Ultra High Magnetic Field

“…At an early stage, the use of MAS NMR correlation spectroscopy to resolve the structure of a uniformly enriched solid has been demonstrated for self-aggregated chlorophyll a/H 2 O (1,11). Chl a constitutes the green pigment in the photosynthetic apparatus of plants as well as algae and cyanobacteria.…”

Solid‐state NMR for the analysis of high‐affinity ligand/receptor interactions

“…Under these conditions the spin diffusion between the protons is suppressed and the polarization transfer is limited to sites where direct heteronuclear dipolar couplings are present and not those which are relayed between the protons. In favorable cases, this has enabled heteronuclear contacts between molecules to be observed (68).…”

“…For these techniques to work effectively, it is necessary to employ relatively short CP times to minimize spin-diffusion effects during the CP or perform the CP while decoupling the proton homonuclear dipolar couplings. Typically, this is achieved by performing CP while spin-locking the proton magnetization at the Lee-Goldberg condition thereby suppressing the strong homo-nuclear dipolar interactions (68)(69)(70). Under these conditions the spin diffusion between the protons is suppressed and the polarization transfer is limited to sites where direct heteronuclear dipolar couplings are present and not those which are relayed between the protons.…”

Magic Angle Spinning Nuclear Magnetic Resonance of the Chlorosomes

“…Chl a can only form solid aggregates by incorporation of H 2 O, which is believed to coordinate the central magnesium atom and form hydrogen bonds with the carbonyl functions of surrounding molecules. Recent MAS NMR results suggest a close homology between the structure of Chl a/H 2 O and crystalline ethyl-chlorophyllide a, with two water molecules forming the bridging network de Boer et al, 2002;van Rossum et al, 2002).…”

“…Complete 1 H and 13 C assignments were obtained in a fi eld of 14.1 T using the 13 C-13 C radio frequencydriven dipolar recoupling (RFDR) and 1 H-13 C Lee Goldburg/cross polarization (LG-CP) methods (van Rossum et al, 2002) (see Table S1 in Supplementary Material). The line widths are small (120-200 Hz) revealing a rigid and well-ordered structure.…”