高解像度NMRリラクソメトリーによって明らかにされたタンパク質のナノ秒時間スケールの動き
Cyril Charlier1, Shahid Nawaz Khan, Thorsten Marquardsen
1Laboratoire des Biomolécules, Département de Chimie, UMR 7203 CNRS-UPMC-ENS, Ecole Normale Supérieure , 24 Rue Lhomond, 75231 Paris Cedex 05, France.
Journal of the American Chemical Society
|November 16, 2013
まとめ
この研究は,幅広い磁場におけるタンパク質の動態を分析する新しい方法を導入し,これまで見過ごされていたナノ秒の動きを明らかにします. この高解像度リラクソメトリー技術は,タンパク質の構造と機能のより深い洞察を提供します.
科学分野:
- バイオフィジックス 生物物理学
- 構造生物学 構造生物学とは
- 核磁共振 (NMR) スペクトロスコピー
背景:
- タンパク質の機能は,その構造と原子レベルのダイナミクスと密接に関連しています.
- NMRにおける核リラクゼーション率は,タンパク質のダイナミクスに関する洞察を提供しますが,典型的には高磁場に限定されます.
- 高磁場は,観測可能な分子運動の周波数範囲を制限し,潜在的に重要なダイナミクスを無視します.
研究 の 目的:
- タンパク質のダイナミクスを特徴付けるための新しい高解像度リラクソメトリー技術を開発し,適用する.
- 広範囲の磁場でタンパク質の分子運動を調査する.
- タンパク質のナノ秒時間スケールの動きを明らかにするために,通常は従来のハイフィールドNMR研究で見逃されます.
主な方法:
- 高フィールド信号検出と低フィールド縦断リラクゼーション (0.514.1 T) を交互にするために高速シャトル装置を使用しました.
- 吹き銃のようなシステムを採用し,サンプルを50秒以内に50cmまでの距離に推進しました.
- 広い磁場スペクトルにわたるタンパク質ウビキチンの窒素15のリラックスデータを分析した.
主要な成果:
- 重要なタンパク質領域におけるナノ秒時間スケールにおける有意な構造的変動を特定しました.
- 伝統的な高フィールドNMRがナノ秒の動きを過小評価する可能性があることを実証しました.
- リラックスの影響を受けない,より遅い動きは,従来の研究で過大評価される可能性があることを示した.
結論:
- 高解像度リラクソメトリーは,タンパク質の分子動力学に関する前例のない洞察を提供します.
- この技術は,タンパク質におけるナノ秒運動の定量的な特徴づけを可能にします.
- この発見は,タンパク質動力学に関する以前の仮定に異議を唱え,マルチフィールドのリラクゼーション研究の重要性を強調しています.
さらに関連する動画
関連する概念動画
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
995
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
995
Atomic Nuclei: Types of Nuclear Relaxation
1.1K
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers...
1.1K
¹H NMR of Labile Protons: Temporal Resolution
1.4K
Protons bonded to heteroatoms such as nitrogen and oxygen exhibit a range of chemical shift values. This is due to the varying degree of hydrogen bonding between the proton and the heteroatom in other molecules. The extent of hydrogen bonding affects the electron density around the proton, thereby giving different chemical shift values for the protons in the proton NMR spectrum.
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the...
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the...
1.4K
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.4K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.4K
2D NMR: Overview of Homonuclear Correlation Techniques
807
Homonuclear correlation spectroscopy (COSY) is a powerful technique used in Nuclear Magnetic Resonance (NMR) spectroscopy to study the correlations between nuclei of the same type within a molecule. It provides information about scalar couplings between adjacent nuclei, which helps determine connectivity and structural information. There are several COSY variants, each with its unique strengths and experimental parameters.
COSY90 is the standard two-dimensional (2D) COSY experiment that...
COSY90 is the standard two-dimensional (2D) COSY experiment that...
807
NMR Spectrometers: Resolution and Error Correction
994
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
994


