電子捕獲解離は,自由基反応のカスケードを開始します
Nancy Leymarie1, Catherine E Costello, Peter B O'Connor
1Department of Biochemistry, Boston University School of Medicine, 715 Albany Street, R806, Boston, Massachusetts 02118, USA.
Journal of the American Chemical Society
|July 17, 2003
まとめ
小型の周期性ペプチドの電子捕捉解離 (ECD) により,予期せぬアミノ酸損失が生じる. ラジカル移住を含む新しいメカニズムは,ペプチド断片化における多重な脊髄と横鎖の裂け目を説明する.
科学分野:
- マススペクトロメトリーによる質量スペクトロメトリーです.
- 化学ダイナミクス 化学ダイナミクス
- プロテオミクス プロテオミクスは,プロテオミクスの
背景:
- 電子捕捉解離 (ECD) はペプチド配列決定の重要な技術である.
- 断片化メカニズムを理解することは,ペプチドの正確な識別に不可欠です.
- 小型の循環性ペプチドは,線形ペプチドと比較してユニークな断片化課題を提示します.
研究 の 目的:
- ECDを用いた小型の周期性ペプチドの断片化パターンを調査する.
- 観察された断片化経路に起因する根本的なメカニズムを解明する.
- 実験的観測に基づいた既存のECD理論を精錬する.
主な方法:
- 高解像度の質量スペクトロメトリーは,断片化製品を分析するために使用されました.
- 周期性ペプチドと線形ペプチドの断片化パターンの比較.
- ラジカル伝播を解釈するための計算モデリングとメカニズム研究.
主要な成果:
- 周期性ペプチドのECDは,アミノ酸の損失とサイドチェーンの割れ目を含む広範な断片化を引き起こしました.
- アミノ酸の損失は,単一の電子捕獲イベントから複数のバックボーン割れを必要とし,予想外によく見られた.
- サイクリックペプチドでは,線形ペプチドと比較して,サイドチェーンの割れ目が増幅された.
結論:
- 現在のECDメカニズムは,複数のバックボーン割れ目を考慮するために,再解釈する必要があります.
- 非エルゴディック電子捕獲とペプチド骨幹に沿った急性伝播を含む改変されたメカニズムが提案されています.
- この急進的移住は,循環ペプチドの複数の脊髄と横鎖の分裂を含む,観察された広範な断片化を説明する.
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