A DOQSY approach for the elucidation of torsion angle distributions in biopolymers: Application to silk

Beek, Jacco D. van; Meier, Beat H.

doi:10.1016/j.jmr.2005.09.004

Cited by 14 publications

(21 citation statements)

References 78 publications

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“…The approach shown in this work is applicable to many other samples which are available in limited amounts. While most studies in biomolecular solid state NMR are carried out under MAS, there are still a number of important examples where static samples are studied [57–59]. Possible applications includes studies of oriented samples such as peptides and proteins incorporated into phospholipid bilayers [60–63].…”

Section: Discussionmentioning

confidence: 99%

Dynamic nuclear polarization-enhanced 1H–13C double resonance NMR in static samples below 20 K

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Thurber

Yau

et al. 2012

Journal of Magnetic Resonance

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We demonstrate the feasibility of one-dimensional and two-dimensional 1H–13C double resonance NMR experiments with dynamic nuclear polarization (DNP) at 9.4 T and temperatures below 20 K, including both 1H–13C cross-polarization and 1H decoupling, and discuss the effects of polarizing agent type, polarizing agent concentration, temperature, and solvent deuteration. We describe a two-channel low-temperature DNP/NMR probe, capable of carrying the radio-frequency power load required for 1H–13C cross-polarization and high-power proton decoupling. Experiments at 8 K and 16 K reveal a significant T2 relaxation of 13C, induced by electron spin flips. Carr–Purcell experiments and numerical simulations of Carr–Purcell dephasing curves allow us to determine the effective correlation time of electron flips under our experimental conditions. The dependence of the DNP signal enhancement on electron spin concentration shows a maximum near 80 mM. Although no significant difference in the absolute DNP enhancements for triradical (DOTOPA-TEMPO) and biradical (TOTAPOL) dopants was found, the triradical produced greater DNP build-up rates, which are advantageous for DNP experiments. Additionally the feasibility of structural measurements on 13C-labeled biomolecules was demonstrated with a two-dimensional 13C–13C exchange spectrum of selectively 13C-labeled β-amyloid fibrils.

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Section: Discussionmentioning

confidence: 99%

Dynamic nuclear polarization-enhanced 1H–13C double resonance NMR in static samples below 20 K

Потапов

Thurber

Yau

et al. 2012

Journal of Magnetic Resonance

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“…The relative orientation of the two chemical shift tensors is encoded in the correlation of the sum of the two tensors with each of the individual tensors. The relative orientation of the dipolar vector with respect to the two chemical shift tensors will additionally modulate the spectra (81). A Ramachandran plot of simulated DOQSY spectra is presented in Fig.…”

Section: Measurement Of Torsion Angles By Doqsymentioning

confidence: 99%

“…Ideally, the principle values of the CSA tensor would be determined for each specific structural motif. The influence of all the assumptions and experimental parameters are thoroughly discussed by van Beek and Meier in a recent article (81).…”

Section: Measurement Of Torsion Angles By Doqsymentioning

confidence: 99%

“…An inherent symmetry in the experiment makes it impossible to distinguish (F, C) from (ÀF, ÀC) torsion angle pairs but this limitation can be overcome by complementing DOQSY data with isotropic chemical shift information (75,81). The sensitivity of the approach with respect to torsion angle distributions allowed these authors to extract the probability distribution functions of torsion angle pairs for alanine residues in Samia cynthia ricini silk.…”

Section: Measurement Of Torsion Angles By Doqsymentioning

confidence: 99%

“…but can give access, if coupled to a careful spectral analysis (81,82), to torsion-angle distributions. Moreover, the double-quantum excitation step provides great control on the spatial selectivity of the experiment when compared with the spin diffusion experiment (81).…”

Section: Measurement Of Torsion Angles By Doqsymentioning

confidence: 99%

See 2 more Smart Citations

Studying natural structural protein fibers by solid‐state nuclear magnetic resonance

Arnold

Marcotte

2009

Concepts Magnetic Resonance

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As a consequence of evolutionary pressure, various organisms have developed structural fibers displaying a range of exceptional mechanical properties adapted specifically to their functions. An understanding of these properties at the molecular level requires a detailed description of local structure, orientation with respect to the fiber and size of constitutive units, and dynamics on various timescales. The size and lack of long-range order in these protein systems constitute an important challenge to classical structural techniques such as high-resolution NMR and X-ray diffraction. Solidstate NMR overcomes these constraints and is uniquely suited to the study of these inherently disordered systems. Solid-state NMR experiments developed or applied to determine structure, orientation, and dynamics of these complex proteins will be reviewed and illustrated through examples of their applications to fibers such as spider and silkworm silks, collagen, elastin, and keratin.

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Solid‐State NMR Spectroscopy of Biopolymers

Taylor

Marius

Ford

et al. 2013

Handbook of Biopolymer‐Based Materials

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A DOQSY approach for the elucidation of torsion angle distributions in biopolymers: Application to silk

Cited by 14 publications

References 78 publications

Dynamic nuclear polarization-enhanced 1H–13C double resonance NMR in static samples below 20 K

Dynamic nuclear polarization-enhanced 1H–13C double resonance NMR in static samples below 20 K

Studying natural structural protein fibers by solid‐state nuclear magnetic resonance

Solid‐State NMR Spectroscopy of Biopolymers

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