回転する固体における周波数選択的異核二極再結合:均一に標識されたペプチドにおける正確な (13) C-(15) N 距離測定 (13) C,(15) N
C P Jaroniec1, B A Tounge, J Herzfeld
1Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Journal of the American Chemical Society
|July 27, 2001
まとめ
周波数選択REDOR (FSR) という新しいマジック・アングル・スピニング・NMR法により,固体における正確な (13) C-(15) N距離測定が可能になる. このテクニックは,選択的に1つの異性核相互作用を再結合し,他のものを抑制し,正確な核間距離データを得ます.
科学分野:
- 固体核磁共振 (NMR) スペクトロスコーピー. 固体核磁共振 (NMR) スペクトロスコーピー. 固体核磁共振 (NMR) スペクトロスコーピー. 固体核磁共振 (NMR) スペクトロスコーピー.
- 構造生物学と生体物理学.
- 材料科学. 材料科学. 材料科学. 材料科学. 材料科学. 材料科学. 材料科学.
背景:
- 正確な核間距離測定は,固体内の分子構造を決定するために不可欠です.
- 均一に標識されたサンプルの複数の (13) C-(15) Nおよび (13) C-(13) C相互作用は,選択的な距離測定を複雑にします.
- 弱い (13) C-(15) N二極結合は,複雑なスピンシステムで正確に測定することは困難です.
研究 の 目的:
- 選択的 (13) C-(15) N 距離測定のための新しいマジック・アングル・スピニング NMR 実験を開発する.
- 複雑な,均一にラベル付けされた固体サンプルにおける既存の方法の限界を克服するために.
- 2.5~6 Å の範囲の複数の核間距離の正確な測定を可能にします.
主な方法:
- 周波数選択スピンエコーとREDOR (回転エコー二重共鳴) パルスシーケンスを組み合わせた.
- 単一の (13) C-(15) N 二極相互作用の選択的再結合.
- 他の (13) C-(15) N二極結合とすべての (13) C-(13) Cスカラー結合の抑制.
- 分析モデルに実験データの最小二乗のフィッティングによる (13) C-(15) N カップルの抽出.
主要な成果:
- 周波数選択REDOR (FSR) 実験の実証, (13) C,(15) Nで均一に標識されたアスパラジン,N-アセチル-L-Val-L-Leu,およびN-フォーミル-L-メット-L-Leu-L-Phe.
- N-formyl-[U-(13) C,(15) N]L-Met-L-Leu-L-Phe.の2.5~6 Åの範囲の16個の核間距離の決定に成功しました.
- マルチスピンシステムにおける弱い (13) C-(15) N 二極結合の正確な測定.
結論:
- FSR実験は,固体NMRでの選択的 (13) C-(15) N距離測定のための強力な新しいツールを提供します.
- この方法は,均一に標識されたサンプルでの距離測定の精度と選択性を大幅に改善します.
- FSRは,バイオ分子と材料の詳細な構造的特徴を容易にします.
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