溶液およびリポソームの多不飽和脂肪酸およびステロールの過酸化速度定数
Libin Xu1, Todd A Davis, Ned A Porter
1Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, USA.
Journal of the American Chemical Society
|August 27, 2009
まとめ
この研究では,リノリエートラジカルクロックを使用して脂質オート酸化率を定量化し,溶液とリポソームの異なる反応性傾向を明らかにしました. この発見は,環境要因が脂質酸化運動と産物形成にどのように影響するかを強調しています.
科学分野:
- バイオケミストリー バイオケミストリー
- 物理化学 物理化学
- リピドミクスは,リピドミクスのことです.
背景:
- オート酸化は,脂質分解の重要なプロセスです.
- 脂質酸化運動の理解は,様々な生物学的および工業的な応用において極めて重要です.
- 以前の脂質自己酸化率の測定方法には限界がありました.
研究 の 目的:
- 溶液中の不飽和脂質とリポソームの自己酸化伝播の速度定数を決定する.
- 異なる多不飽和脂肪酸とステロールの自己酸化における反応性を比較する.
- 局所脂質環境が過酸化ラジカルの行動に及ぼす影響を調査する.
主な方法:
- 水素原子抽象化とベータ断片化に基づくリノリエート基数時計を使用しました.
- 37°Cでベンゼン溶液中の様々な脂質の測定速度定数.
- コレステロールまたは7-デヒドロコレステロールを含むまたは含まない,フォスファディチルコリンリポソームの自由根酸化を行った.
- 結合ダイエンの酸化産物 (トランス,シス/トランス,トランス) の比率を分析して,リポソームにおける相対的自己酸化伝播速度の定数を決定した.
主要な成果:
- 溶液では,リノール酸に対する速度定数は,脂肪酸鎖の長さと不飽和度 (アラキドン酸,イコサペンタエノ酸,ドコサヘキサエノ酸) により増加した.
- コレステロールは溶液中の低反応性を示したが,7デヒドロコレステロールは高い反応性を示した.
- リポソームの研究では,多不飽和脂肪酸と7-デヒドロコレステロールの反応性傾向が類似していることが明らかになった.
- リノレート鎖の異なる位置にあるペロキシルラジカルは,溶液と異なり,リポソームに独特の運動特性を示した.
結論:
- リノレートラジカルクロックは,溶液と脂質双層の両方で,自己酸化伝播速度を効果的に定量化します.
- 脂質自己酸化反応性は,分子構造と局所環境の両方によって影響を受けます.
- ペロキシルラジカルベータ分裂は溶媒の極性に対して敏感であり,リポソーマ環境は位置に基づいてラジカル行動に影響を与える.
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