A simple analytical model to describe dynamic magic‐angle spinning experiments

Hirschinger, Jérôme

doi:10.1002/cmr.a.20064

Cited by 22 publications

(17 citation statements)

References 50 publications

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“…where τ s is a correlation time due to slower isotropic molecular motions originating from the diffusion between bilayers with different orientations of their principal symmetry axis, and the cosine terms are the contribution from MAS of the sample, rotating at ω R /2π cycles per second, 26 typically in the kHz frequency range. We expect a two step model behavior 27 of the correlation function g(τ) as illustrated in Figure 1 and described as follows.…”

Section: Auto-correlation Functionmentioning

confidence: 99%

Model-free estimation of the effective correlation time for C–H bond reorientation in amphiphilic bilayers: 1H–13C solid-state NMR and MD simulations

Ferreira

Ollila

Pigliapochi

et al. 2015

The Journal of Chemical Physics

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Molecular dynamics (MD) simulations give atomically detailed information on structure and dynamics in amphiphilic bilayer systems on timescales up to about 1 μs. The reorientational dynamics of the C-H bonds is conventionally verified by measurements of (13)C or (2)H nuclear magnetic resonance (NMR) longitudinal relaxation rates R1, which are more sensitive to motional processes with correlation times close to the inverse Larmor frequency, typically around 1-10 ns on standard NMR instrumentation, and are thus less sensitive to the 10-1000 ns timescale motion that can be observed in the MD simulations. We propose an experimental procedure for atomically resolved model-free estimation of the C-H bond effective reorientational correlation time τe, which includes contributions from the entire range of all-atom MD timescales and that can be calculated directly from the MD trajectories. The approach is based on measurements of (13)C R1 and R1ρ relaxation rates, as well as (1)H-(13)C dipolar couplings, and is applicable to anisotropic liquid crystalline lipid or surfactant systems using a conventional solid-state NMR spectrometer and samples with natural isotopic composition. The procedure is demonstrated on a fully hydrated lamellar phase of 1-palmitoyl-2-oleoyl-phosphatidylcholine, yielding values of τe from 0.1 ns for the methyl groups in the choline moiety and at the end of the acyl chains to 3 ns for the g1 methylene group of the glycerol backbone. MD simulations performed with a widely used united-atom force-field reproduce the τe-profile of the major part of the acyl chains but underestimate the dynamics of the glycerol backbone and adjacent molecular segments. The measurement of experimental τe-profiles can be used to study subtle effects on C-H bond reorientational motions in anisotropic liquid crystals, as well as to validate the C-H bond reorientation dynamics predicted in MD simulations of amphiphilic bilayers such as lipid membranes.

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Section: Auto-correlation Functionmentioning

confidence: 99%

Model-free estimation of the effective correlation time for C–H bond reorientation in amphiphilic bilayers: 1H–13C solid-state NMR and MD simulations

Ferreira

Ollila

Pigliapochi

et al. 2015

The Journal of Chemical Physics

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“…The broadening of these lines is likely due to the fact that the reorientation of the DLPS phosphate group is on the same time scale as the magic-angle spinning (τ C ≈ 1 ms). 18,19 Altogether, the 13 C and 31 P MAS NMR measurements show that the coassembly of DMPS and DLPS molecules with α-synuclein into amyloid proto-fibrils decreases the rate and the anisotropy of their reorientation (see illustration in Figure 4).…”

mentioning

confidence: 91%

Lipid Dynamics and Phase Transition within α-Synuclein Amyloid Fibrils

Galvagnion

Topgaard

Makasewicz

et al. 2019

J. Phys. Chem. Lett.

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The deposition of coassemblies made of the small presynaptic protein, α-synuclein, and lipids in the brains of patients is the hallmark of Parkinson’s disease. In this study, we used natural abundance 13C and 31P magic-angle spinning nuclear magnetic resonance spectroscopy together with cryo-electron microscopy and differential scanning calorimetry to characterize the fibrils formed by α-synuclein in the presence of vesicles made of 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine or 1,2-dilauroyl-sn-glycero-3-phospho-L-serine. Our results show that these lipids coassemble with α-synuclein molecules to give thin and curly amyloid fibrils. The coassembly leads to slower and more isotropic reorientation of lipid molecular segments and a decrease in both the temperature and enthalpy of the lipid chain-melting compared with those in the protein-free lipid lamellar phase. These findings provide new insights into the properties of lipids within protein–lipid assemblies that can be associated with Parkinson’s disease.

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“… DIPSHIFT curves as a function of dynamic rate on NMR timescale. The lines are model fits assuming diffusive anisotropic motions under the Anderson‐Weiss approximation from UiO‐66 data at various temperatures (see the Supporting Information). The curves correspond to estimated correlation times ( τ c ) of ms or the rigid limit (dark blue), approximately 350 μs (light blue), approximately 5 μs (yellow), and the fast limit below one microsecond (red).…”

Section: Figurementioning

confidence: 99%

The Influence of Chemical Modification on Linker Rotational Dynamics in Metal–Organic Frameworks

Damron

Kurz³

et al. 2018

Angewandte Chemie

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The robust synthetic flexibility of metal-organic frameworks (MOFs) offers ap romising class of tailorable materials,for which the ability to tune specific physicochemical properties is highly desired. This is achievable only through at horough description of the consequences for chemical manipulations both in structure and dynamics.M agic angle spinning solid-state NMR spectroscopyoffers many modalities in this pursuit, particularly for dynamic studies.H erein, we employaseparated-local-field NMR approach to show how specific intraframework chemical modifications to MOF UiO-66 heavily modulate the dynamic evolution of the organic ring moiety over several orders of magnitude.Metal-organic frameworks (MOFs) are constructed from inorganic clusters bridged by organic linkers and possess ideal architectures for gas storage and mixture separation as well as generating recent interest as nanodevices and molecular machines. [1] In comparison to traditional inorganic porous materials,M OFs are far more dynamic/flexible due to the incorporation of organic ligands. [2][3][4] Ak ey advantage of MOFs is the synthetic ease of chemical modification to the organic moieties without change of framework structure, known as isoreticular synthesis.This allows for many avenues of functional modification including adsorptive selectivity based on favorable ligand-guest interactions, [5] changes in pore aperture for separations, [6,7] and shifts in optical behavior. [8] An additional feature of MOFs,w hich has captured much attention, is the prevalence of framework dynamics which can lead to dramatic structural shifts such as breathing, swelling,a nd subnetwork displacements. [9,10] While deformations in the metal cluster have been implicative of dynamic events,the nature of the linker and its functionality is amajor contributor to framework dynamics, [10] and play as ignificant role in determining macroscopic functions such as gas storage and separation, ferroelectricity,s pin crossover and luminescence in av ariety of MOFs. [11][12][13][14][15][16][17] As such, establishing relationships between local dynamics driven by the organic ligands and their chemical modification is of general interest for materials design in MOFs. [17,18] Though the structural picture of MOFs is most informed by analysis with X-ray diffraction, this yields an essentially static picture,f ailing to capture the dynamic aspects of the framework. However,dynamic measures of crystalline materials are challenging due to the potential of multiple timescales of coordinated motions in the solid-state.M any dynamic studies have employed solid-state NMR spectroscopy (ssNMR) through 2 H-lineshape analysis to characterize the rotational motion of simple p-phenylene rings within the MOF framework. [15,[19][20][21][22][23][24] Separated-local-field (SLF) solidstate NMR spectroscopy is an alternative,attractive means of dynamic characterization as it uses the heteronuclear dipolar coupling as aproxy for molecular dynamics,does not require isotopic labeling, and can be used t...

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A simple analytical model to describe dynamic magic‐angle spinning experiments

Cited by 22 publications

References 50 publications

Model-free estimation of the effective correlation time for C–H bond reorientation in amphiphilic bilayers: 1H–13C solid-state NMR and MD simulations

Model-free estimation of the effective correlation time for C–H bond reorientation in amphiphilic bilayers: 1H–13C solid-state NMR and MD simulations

Lipid Dynamics and Phase Transition within α-Synuclein Amyloid Fibrils

The Influence of Chemical Modification on Linker Rotational Dynamics in Metal–Organic Frameworks

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