Labeling segmental

Tzakos AG, Easton EE, Lukavsky PJ. Preparation of large RNA oligonucleotides with complementary isotope-labeled segments... 

Most recently, a double-quantum solid-state NMR technique has been reported [47]. This gives detailed structural information such as torsion angles for unoriented amorphous polymers including unoriented polypeptides with NMR tensor correlation in the labeled segments. This new solid-... 

Solid state NMR measurements for the complex of an 18-residue peptide have been reported. The peptide molecule was uniformly N- and C-labelled in a 7-residue segment containing the conserved GPGR motif in the epitope. N and NMR chemical shift assignments for the labelled segment were obtained from 2D and N- C MAS NMR spectra. Reductions in NMR... 

Self-diffusion type measurements. A radiotracer of a specific form is chemical mixed with a solid and the diffusion into the non-labelled segment of the same material is measured. The procedure yields information on matrix restriction caused by pore stmcture and water content when a non-reactive component is introduced (Na-22, Cl-38 and H-3). For reactive species it will yield information on the distribution ratio between liquid and solid phase, which can be expressed as a retardation factor. By introducing components of interest in different chemical forms the mobilities of these different species in a given matrix can be determined. Analysis of diffusion profiles may result in identification of more then one species. 

The issue of partly hydrogenated trans- fii. (generally labeled segmented /ran -PA) was the center of interest for a few years and then faded without a detailed final agreement between the communities of physically oriented and chemically oriented researchers. 

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