Relaxation nuclear magnetic resonance

The combined effects of temperature and pressure on nuclear magnetic relaxation have been studied to obtain the derivative (dr/dP), from spin-lattice relaxation time measurements as well as dT/bP at constant line width in the region of line narrowing.Even at a single frequency, the determination can be made at various temperatures. The spin-lattice measurement corresponds to frequencies of the order of 10 Hz the spin-spin or line width measurement, of lO Hz. The lower the temperature, the more short range is the character of the motions reflected at a given frequency and the numerical values for (ibT/bP) appear to decrease with decreasing temperature for natural rubber, cw-polybutadiene, and other poly- 

---

Lipari G and Szabo A 1982 Model-free approach to the interpretation of nuclear magnetic resonance relaxation in macromolecules 1. Theory and range of validity J. Am. Chem. Soc. 104 4546-59... 

The use of computer simulations to study internal motions and thermodynamic properties is receiving increased attention. One important use of the method is to provide a more fundamental understanding of the molecular information contained in various kinds of experiments on these complex systems. In the first part of this paper we review recent work in our laboratory concerned with the use of computer simulations for the interpretation of experimental probes of molecular structure and dynamics of proteins and nucleic acids. The interplay between computer simulations and three experimental techniques is emphasized (1) nuclear magnetic resonance relaxation spectroscopy, (2) refinement of macro-molecular x-ray structures, and (3) vibrational spectroscopy. The treatment of solvent effects in biopolymer simulations is a difficult problem. It is not possible to study systematically the effect of solvent conditions, e.g. added salt concentration, on biopolymer properties by means of simulations alone. In the last part of the paper we review a more analytical approach we have developed to study polyelectrolyte properties of solvated biopolymers. The results are compared with computer simulations. 

Fushman, D. and D. Cowburn, Nuclear magnetic resonance relaxation in determination of residue-specific 1SN chemical shift tensors in proteins in solution protein dynamics, structure, and applications of transverse relaxation optimized spectroscopy, in Methods Enzymol. T. James, U. Schmitz, and V. Doetsch, Editors. 2001. p.109-126. 

Lipari G. and Szabo A. (1980) Effect of Vibrational Motion on Fluorescence Depolarization and Nuclear Magnetic Resonance Relaxation in Macromolecules and Membranes, Biophys. J. 30, 489—506. Steiner R. F. (1991) Fluorescence Anisotropy Theory and Applications, in Lakowicz J. R. (Ed.), Topics in Fluorescence Spectroscopy, Vol. 2, Principles, Plenum Press, New York, pp. 127-176. 

Lipari G. and Szabo A. (1980) Effect of Vibrational Motion on Fluorescence Depolarization and Nuclear Magnetic Resonance Relaxation in Macromolecules and Membranes, Biophys. J. 30, 489-506. 

V. I. Bakhmutov, Practical Nuclear Magnetic Resonance Relaxation for Chemists, Wiley, Hoboken, NJ (2005). 

Keywords Colloids, Nuclear Magnetic Resonance, Relaxation, Diffusion. 

ROder O, LUdemann HD, von Goldammer E (1975) Determination of the activation energy for pseudorotation of the furanose ring in nucleosides by 13C nuclear-magnetic resonance relaxation. Eur J Biochem 53 517-524... 

R272 E. E. Burnell, D. Capitani, C. Casieri and A. L. Segre, A Proton Nuclear Magnetic Resonance Relaxation Study of C12E6/D2O , J. Phys. Chem. B, 2000,104, 8782... 

Deczky, K., and Langford, H. (1978). Apphcation of water nuclear magnetic resonance relaxation times to study of metal complexes of the soluble soil organic matter fraction fulvic acid. Can. J. Chem. 56, 1947-1951. 

J. McConnel, Nuclear Magnetic Resonance Relaxation in Liquids. Cambridge University Press, Cambridge, 1986. 

Historically, hydrogen exchange experiments (i.e., the replacement of one isotope of hydrogen bound to an O, N, or S atom in the protein interior by another isotope from the solvent water) provided some of the earliest evidence for the existence of conformational fluctuations in proteins. More recently, a wide range of experimental methods (such as fluorescence quenching and depolarization, nuclear magnetic resonance relaxation, infrared and Raman spectroscopy, and X-ray and inelastic neutron scattering) have been used to study the motions in proteins. However, it is primarily the application of theoretical methods, particularly molecular dynamics simulations, that have... 

The nuclear magnetic resonance relaxation times for the protons of water adsorbed to saturation in a high-purity specimen of zeolite 13-X have been measured between 200° and 500°K. The data can be accounted for by the model of an intracrystalline fluid which is about 30 times as viscous as bulk water at room temperature, shows a broad distribution of molecular mobilities, and is about as dense as liquid water. The median correlation time (time between molecular flights) is... 

R. Blinc and G. Lahajnar, "Nuclear-magnetic-resonance relaxation by spin-rotational interactions in the solid," Phys, Rev. Letters 19, 685-687 (1967). 

Kuntz, G. P. P., and Kotowycz, G. (1975). Biochemistry 14, 4144. A Nuclear Magnetic Resonance Relaxation Time Study of the Manganese(II)-Inosine 5 -Triphosphate Complex in Solution. 

Roder, 0., Ludemann, H. D., and Von Goldammer, E. (1975). Eur. J. Biochem. 53, 517. Determination of the Activation Energy for Pseudorotation of the Furanose Ring in Nucleosides by 13C Nuclear Magnetic Resonance Relaxation. 

Nicolau, Cl., Dreeskamp, H., and Schultc-Frohlinde, D. (1974). FEBS Lett. 43, 148. I3C Nuclear Magnetic Resonance Relaxation Measurements of tt-I.eci-thin-Peptide Interaction in Model Membranes. 

Kalyanasundaram, K., Gratzel, M., and Thomas, J. K. (1975). J. Amer. Chem. Soc. 97, 3915. Electrolyte-Induced Phase Transitions in Micellar Systems. A Proton and Carbon-13 Nuclear Magnetic Resonances Relaxation and Photochemical Study. 

The kinetics of the protolysis of methylammonium ion in aqueous solution has been studied with nuclear magnetic resonance. Relaxation times were obtained by studying the CH3, and H2O resonances as a function of pH and methylammo-... 

We define the hydration number as the average number of water molecules in the first sphere about the metal ion. The residence time of these molecules is determined generally by the nature of the bonding to the metal ion. For the f-element cations, ion-dipole interactions result in fast exchange between the hydration layer and the bulk solvent. The techniques for studying the nature (number and/or structure) of the hydration shell can be classified as either direct or indirect methods. The direct methods include X-ray and neutron diffraction, luminescence and NMR (nuclear magnetic resonance) relaxation measurements. The indirect methods involve compressibility, NMR exchange and absorption spectroscopy measurements. 

Nuclear magnetic resonance relaxation is a useful experimental technique to study surfactant aggregation in liquid solutions and liquid crystals [2,50,51]. It yields information on the local dynamics and the conformational state of the surfactant hydrocarbon chain and has, for example, demonstrated the liquidlike interior of surfactant micelles. However, the aim of NMR relaxation studies of microemulsions is often to study properties such as the surfactant aggregate (droplet) size. 

Stark R.E., Garbow J.R., Nuclear magnetic resonance relaxation studies of plant polyester dynamics. 2. Suberized potato cell walls. Macromolecules, 25, 1992,149-154. 

R. Richarz, K. Nagayama, K. Wiithrich, Carbon-13 nuclear magnetic resonance relaxation studies of internal mobility of the polypeptide chain in basic pancreatic trypsin inhibitor and a selectively reduced analog. Biochemistry 19 (1980) 5189—5196. 

Levine, Y.K., BirdsaU, N.J.M., Lee, A.G., and Metcalfe, J.C. 1972. nuclear magnetic resonance relaxation measurements of synthetic lecithins and the effect of spin-labeled lipids. Biochemistry 11 1416—1421. Levitt, M.H. 2008. SpinDynamics. New York John Wiley Sons. 

It was possible to rationalize the family of Arrhenius plots measured for Nafion 117 at different water contents [46]. Under an assumption that the surface conductivity has higher activation energy, supported by microscopic considerations in Refs. 40, 43, the Arrhenius slope should become steeper with the decreasing amount of water in the membrane [39], that is, the smaller the amount of the bulk water that we have in pores. Activation energies obtained from these plots are 0.1 eV for the largest possible water contents (Activation energies of proton transfer in water, estimated from nuclear magnetic resonance relaxation times, are 0.1 eV [47].) and 0.3-0.4eV at small water contents. How to rationalize this variation. ... 

Nuclear Magnetic Resonance—Relaxation Time Measurements. 

Extracellular polysaccharides composed of o-glucose, pyruvic acid, and succinic acid have been isolated from a number of strains of Agrobacterium. The conformational behaviour of the extracellular gel-forming polysaccharides from Arthrobacter species has been investigated by nuclear magnetic resonance relaxation and optical rotation techniques. " A number of the polysaccharides studied showed evidence of an ordered conformation which could be melted out on heating. O-Deacetylation destroyed the ordered conformation of two A. viscosus polysaccharides, whilst O-deacylation of the A. stabilis polysaccharide stabilized the ordered structure. 

G. Lipari and A. Szabo, /. Am. Chem. Soc., 104, 4559 (1982). Model-Free Approach to the Interpretation of Nuclear Magnetic Resonance Relaxation in Macromolecules. 2. Analysis... 

---