Nuclear magnetic spin relaxation of a spin-pair undergoing reorientations by jumping among unequivalent sites

Tsutsumi, Atsushi

doi:10.1080/00268977900100101

Cited by 60 publications

(20 citation statements)

References 19 publications

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“…S 2 mm= then can be described by using Eq. [30] or [31] where ACKNOWLEDGMENTS the angle b is approximately equal to 70.5Њ (see Fig. 8).…”

Section: Figmentioning

confidence: 97%

“…In this case, the vector sum of w(t) and c(t) contributions in rotating the C a -C b -H group is directed along the axis which runs perpendicular to the C a -H bond, and the angle b in Eq. [30] or [31] is equal to 90Њ. For fully correlated w(t) and c(t) rotations, i.e., (Rr, Rr) or (rR, rR), the effective rotation axis bisects the angle H-C a -C b , and b in Eqs.…”

Section: Figmentioning

confidence: 99%

“…For fully correlated w(t) and c(t) rotations, i.e., (Rr, Rr) or (rR, rR), the effective rotation axis bisects the angle H-C a -C b , and b in Eqs. [30] and [31] is equal to 54.7Њ. The angles 70.5Њ and 54.7Њ were calculated assuming ideal tetrahedral bond geometry at the C a carbon.…”

Section: Figmentioning

confidence: 99%

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A Novel Model-Free Analysis of13C NMR Relaxation of Alanine-Methyl Side-Chain Motions in Peptides

Daragan

Mayo

1996

Journal of Magnetic Resonance, Series B

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“…S 2 mm= then can be described by using Eq. [30] or [31] where ACKNOWLEDGMENTS the angle b is approximately equal to 70.5Њ (see Fig. 8).…”

Section: Figmentioning

confidence: 97%

Section: Figmentioning

confidence: 99%

See 1 more Smart Citation

A Novel Model-Free Analysis of13C NMR Relaxation of Alanine-Methyl Side-Chain Motions in Peptides

Daragan

Mayo

1996

Journal of Magnetic Resonance, Series B

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“…For example, if we consider the model of two-state rotational jumps between 3'0-3' and %+3' (Tsutsumi, 1979;Daragan and Mayo, 1993b), then SZH = 1 --(8127) sin27(1 + 8cos23')…”

Section: Simple Analysis Of Glycine Motionsmentioning

confidence: 99%

Lysine side-chain dynamics derived from 13C-multiplet NMR relaxation studies on di- and tripeptides

1995

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13C NMR relaxation data have been used to determine dipolar auto- and cross-correlation times for the di- and tripeptides GK, KG, and GKG, primarily to analyze lysine side-chain motional dynamics. In general, correlation times are largest for backbone positions and decrease on going through the lysine side chain, consistent with the idea of increased mobility at C delta and C episilon methylenes. Correlation times, however, vary with the peptide ionization state. In the zwitterionic state of GK, for example, both auto- and cross-correlation times are at their maximum values, indicating reduced internal motions probably resulting from intramolecular electrostatic interactions. Modifying the charge state increases motional fluctuations. Activation energies determined from the temperature dependence of CH rotational autocorrelation times at neutral pH are approximately equal for glycine and lysine C alpha and lysine C beta and C gamma positions (4.1 +/- 0.2 to 4.5 +/- 0.2 kcal/mol) and tend to decrease slightly for lysine C delta and C epsilon (3.8 +/- 0.2 to 4.3 +/- 0.2 kcal/mol). The sign of lysine side-chain cross-correlations could not be explained by using any available rotational model, including one parameterized for multiple internally restricted rotations and anisotropic overall tumbling. Molecular and stochastic dynamics calculations were performed to obtain insight into correlated internal rotations and coupled overall tumbling and internal motions. Relatively strong correlations were found for i,i+1 backbone and lysine side-chain internal bond rotations. Stochastic dynamics calculations were more successful at explaining experimentally observed correlation times. In the fully charged state, a preferred conformation was detected with an all-trans lysine side chain.

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“…The simplest model in which larger amplitude bond rotations are considered is the model of rotational jumps between two equivalent states: Ϫ␥, ϩ␥. For this model, the correlation function ⌽ m,mЈ (t) can be written as 20,25 ⌽ m,mЈ ͑t͒ ϭ cos m␥ cos mЈ␥…”

Section: Motional Models For Nmr Relaxation Data Analysismentioning

confidence: 99%

Angular variances for internal bond rotations of side chains in GXG-based tripeptides derived from13C-NMR relaxation measurements: Implications to protein folding

et al. 1999

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The study of backbone and side‐chain internal motions in proteins and peptides is crucial to having a better understanding of protein/peptide “structure” and to characterizing unfolded and partially folded states of proteins and peptides. To achieve this, however, requires establishing a baseline for internal motions and motional restrictions for all residues in the fully, solvent‐exposed “unfolded state.” GXG‐based tripeptides are the simpliest peptides where residue X is fully solvent exposed in the context of an actual peptide. In this study, a series of GXG‐based tripeptides has been synthesized with X being varied to include all twenty common amino acid residues. Proton‐coupled and ‐decoupled 13C‐nmr relaxation measurements have been performed on these twenty tripeptides and various motional models (Lipari–Szabo model free approach, rotational anisotropic diffusion, rotational fluctuations within a potential well, rotational jump model) have been used to analyze relaxation data for derivation of angular variances and motional correlation times for backbone and side‐chain χ1 and χ2 bonds and methyl group rotations. At 298 K, backbone motional correlation times range from about 50 to 85 ps, whereas side‐chain motional correlation times show a much broader spread from about 18 to 80 ps. Angular variances for backbone ϕ,ψ bond rotations range from 11° to 23° and those for side chains vary from 5° to 24° for χ1 bond rotations and from 5° to 27° for χ2 bond rotations. Even in these peptide models of the “unfolded state,” side‐chain angular variances can be as restricted as those for backbone and β‐branched (valine, threonine, and isoleucine) and aromatic side chains display the most restricted motions probably due to steric hinderence with backbone atoms. Comparison with motional data on residues in partially folded, β‐sheet‐forming peptides indicates that side‐chain motions of at least hydrophobic residues are less restricted in the partially folded state, suggesting that an increase in side‐chain conformational entropy may help drive early‐stage protein folding. © 1999 John Wiley & Sons, Inc. Biopoly 49: 373–383, 1999

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Nuclear magnetic spin relaxation of a spin-pair undergoing reorientations by jumping among unequivalent sites

Cited by 60 publications

References 19 publications

A Novel Model-Free Analysis of13C NMR Relaxation of Alanine-Methyl Side-Chain Motions in Peptides

A Novel Model-Free Analysis of13C NMR Relaxation of Alanine-Methyl Side-Chain Motions in Peptides

Lysine side-chain dynamics derived from 13C-multiplet NMR relaxation studies on di- and tripeptides

Angular variances for internal bond rotations of side chains in GXG-based tripeptides derived from13C-NMR relaxation measurements: Implications to protein folding

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