Relaxation paramagnetic effects

Cr(acac)3 in various perdeuterated solvents, Nilenls in en Paramagnetic relaxation effects on nonexchanging systems 2000 298 H. N 141... 

Next, we turn to the paramagnetic relaxation effects in protein systems. Koehler and Meiler reviewed the utility of measurements of this kind. Here again, I do not aim at providing a full literature review of the field, but rather to give the reader a limited selection of examples. Under certain conditions, the measurements of PRE can provide an alternative method to characterize invisible states in proteins. Anthis et applied this... 

A separation of the paramagnetic relaxation effects into a dipolar and a scalar term is strictly valid only when the g-tensor is isotropic (cf. [343], Chapter 2). In other cases there is an "interference term" between the two. 

High-resolution H n.m.r. spectroscopy has been used to probe the conformations of a number of o-ribofuranosylamine derivatives and such rigid molecules as 2,2 -cyclonucleosides and nucleoside 3, 5 -phosphates in aqueous solution. H N.m.r. spectroscopy has also been used to study details of the intramolecular association and conformations of a- and j8-linked pyridine ribo-nucleosides and their 5 -phosphates. The results were analysed in terms of base-D-ribose, o-ribose-side-chain, and base-side-chain interactions and the conformational restraints imposed by the cis HO-2-HO-3 interaction in jS-nucleo-tides and the additional cis HO-2 -base interaction in a-nucleotides. H N.m.r. measurements - including measurements of nuclear Overhauser effects and paramagnetic relaxations effected by Mn + cations - have been used to investigate the preferred conformation about the jV-glycosidic bond of 8-amino-, 8-methyl-amino-, and 8-dimethylamino-adenylic acid, all of which competitively inhibit the coenzyme NADH in the reaction with chicken-muscle lactate dehydrogenase. The primary and secondary amines were shown to prefer anti conformations, whereas the tertiary amine prefers a syn conformation. 

Using solid-state NMR, a mitochondria-penetrating peptide interacting with the model inner mitochondrial membrane was observed in order to gain insight into the mechanism of translocation. The paramagnetic relaxation effect due to Mn ions on MAS NMR was used to measure... 

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