Combination of cross polarization/magic angle spinning NMR and x-ray crystallography: structure and dynamics in a low-symmetry molecular crystal, potassium penicillin V

1993 ◽  
Vol 115 (13) ◽  
pp. 5636-5650 ◽  
Author(s):  
Jamila Fattah ◽  
J. Mark Twyman ◽  
Stephen J. Heyes ◽  
David J. Watkin ◽  
Alison J. Edwards ◽  
...  
2000 ◽  
Vol 53 (12) ◽  
pp. 971 ◽  
Author(s):  
Eric W. Ainscough ◽  
Andrew M. Brodie ◽  
Peter C. Healy ◽  
Joyce M. Waters

The X-ray crystal structure determination of bis[-(phenylcyanamido)bis(triphenylphosphine)copper(I)], [{Cu(PPh3)2(C6H5NCN)}2], (1) is reported. The complex has a centrosymmetric dimeric structure with the phenylcyanamide ligands bridging the copper atoms in a -1,3-fashion. The structure is compared with that of the 4-methylphenylcyanamido complex, [{Cu(PPh3)2(4-MeC6H4NCN)}2] (2), and the differences observed in the Cu–P bond lengths compared with changes in the solid state 31P cross-polarization magic-angle spinning (CPMAS) spectra of the two complexes.


1987 ◽  
Vol 40 (9) ◽  
pp. 1545 ◽  
Author(s):  
PF Barron ◽  
LM Engelhardt ◽  
PC Healy ◽  
J Oddy ◽  
AH White

Linear, two-coordinate compounds of molecular formula (PPh3) AuX have been characterized by solid-state and solution 31P n.m.r. spectroscopy, and single-crystal X-ray diffraction techniques. The solid state n.m.r. spectra reveal single, broad resonance lines for X = NO3 (chemical shift 19 ppm , ref. 85% H3PO4), CH3C02 (24 ppm), SCN (36ppm), CN (37 ppm ) and CH3 (47 ppm ) and doublets for X = Cl (27, 33 ppm ), Br (28, 36 ppm ) and I (34, 38 ppm ), the latter three spectra being recorded at 121.47 MHz and 161.96 MHz. Solution spectra show relatively sharp single resonances for each compound with 6 values generally slightly higher than in the solid state. Crystal data are reported for X = NO3, space gro )p P21/c, a 8 895(9), b 10.117(8), c 19.57(2) �; β 97.43(8)�, Au-P,O = 2.199(5), 2.02(1) �. Crystals of compounds with X = Br, I and SCN are isomorphous with the AuCl compound, belonging to space group 212121. For X = Br, a 12.479(5), b 13.45(1), c 10.0!2(8) �; Au-P, Br = 2.252(6), 2.407(2) �. For X = I, a 12.529(8), b 13.870(5), c 10.188(4) �; Au-P, I = 2.254(5), 2.556(2) �. For X = SCN, a 12.257(5), b 13.776(8), c 10.754(6) �; Au-P, S = 2.252(7), 2.304(7) �.


2018 ◽  
Vol 115 (13) ◽  
pp. 3237-3242 ◽  
Author(s):  
Anne Diehl ◽  
Yvette Roske ◽  
Linda Ball ◽  
Anup Chowdhury ◽  
Matthias Hiller ◽  
...  

Microorganisms form surface-attached communities, termed biofilms, which can serve as protection against host immune reactions or antibiotics.Bacillus subtilisbiofilms contain TasA as major proteinaceous component in addition to exopolysaccharides. In stark contrast to the initially unfolded biofilm proteins of other bacteria, TasA is a soluble, stably folded monomer, whose structure we have determined by X-ray crystallography. Subsequently, we characterized in vitro different oligomeric forms of TasA by NMR, EM, X-ray diffraction, and analytical ultracentrifugation (AUC) experiments. However, by magic-angle spinning (MAS) NMR on live biofilms, a swift structural change toward only one of these forms, consisting of homogeneous and protease-resistant, β-sheet–rich fibrils, was observed in vivo. Thereby, we characterize a structural change from a globular state to a fibrillar form in a functional prokaryotic system on the molecular level.


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