Dynamic angle spinning probe

Mueller, K.T., Chingas, G.C., and Pines, A. 1991a. A dynamic-angle spinning NMR probe. Rev. Sci. Instrum. 62 1445-1452. 

M.A. Eastman, P.J. Grandinetti, Y.K. Lee, A. Pines, Double-mned hopping-coil probe for dynamic-angle-spinning NMR, J. Magn. Reson. 98 (1992) 333-341. 

The 2,2,6,6-tetramethylpiperidinoxyl radical (TEMPO) was first prepared in 1960 by Lebedev and Kazarnovskii by oxidation of its piperidine precursor.18 The steric hindrance of the NO bond in TEMPO makes it a highly stable radical species, resistant to air and moisture. Paramagnetic TEMPO radicals can be employed as powerful spin probes for elucidating the structure and dynamics of both synthetic and biopolymers (e.g., proteins and DNA) by ESR spectroscopy.19 Unlike solid-phase 1H-NMR where magic angle spinning is required in order to reduce the anisotropic effects in the solid-phase environment, solid-phase ESR spectroscopy can be conducted without specialized equipment. Thus, we conducted comparative ESR studies of various polymers with persistent radical labels, and we also determined rotational correlation times as a function of... 

Accordingly, it is concluded that the NMR signals of [l- C]Val and He residues among a variety of [l- C]amino-acid residues can serve as the most appropriate probes, to examine the local conformation and dynamics of bR from PM especially at the surface area. Otherwise, it should be anticipated that the carbonyl NMR signals are not fully visible from those located at the membrane surface (Ala, Leu, Phe, and Trp), because of interference between the fluctuation frequency and the frequency of magic angle spinning. 

Hughes CE, Haufe S, Angerstein B et al (2004) Probing structure and dynamics in poly[2,2 -(m-phenylene)-5,5 -bibenzimidazole] fuel cells with magic-angle spinning NMR. J Phys Chem 108 13626-13631... 

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