溶液和脂质体中的多不和脂肪酸和固醇过氧化的速率常数
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
概括
这项研究使用烯酸盐基钟量化了脂质自氧化率,揭示了溶液和脂质体的不同反应性趋势. 这些发现突出了环境因素如何影响脂质氧化动力学和产品形成.
科学领域:
- 生物化学 生物化学
- 物理化学 物理化学
- 利皮多米克 (Lipidomics) 是一种消化剂.
背景情况:
- 自氧化是脂质降解中的一个关键过程.
- 了解脂质氧化动力学对于各种生物和工业应用至关重要.
- 以前用于确定脂质自氧化率的方法存在局限性.
研究的目的:
- 为了确定溶液和脂质体中不和脂质的自氧化传播的速率常数.
- 为了比较不同多不和脂肪酸和固醇在自氧化过程中的反应性.
- 为了研究当地的脂质环境对过氧基基行为的影响.
主要方法:
- 使用了基于原子抽象和β碎片化的烯酸基钟.
- 在37°C的烯溶液中的各种脂质的测量速率常数.
- 对酸丁胆脂质体进行了自由基氧化,有或没有胆固醇或7-脱胆固醇.
- 分析了结合二烯氧化产物 (trans,cis/trans,trans) 的比率,以确定脂质体中的相对自氧化传播速率常数.
主要成果:
- 在溶液中,与脂肪酸链长度和不和 (阿拉基酸,eicosapentaenoic,docosahexaenoic酸) 相对的利诺基酸速率常数增加.
- 胆固醇在溶液中的反应性较低,而7-脱胆固醇的反应性较高.
- 脂质体研究显示,多不和脂肪酸和7-脱胆固醇的反应性趋势类似.
- 在酸盐链上不同位置的过氧基在脂质体中表现出不同的动力性质,与溶液不同.
结论:
- 酸基钟有效量化了溶液和脂质双层中的自氧化传播速率.
- 脂质自氧化反应受分子结构和局部环境的影响.
- 过氧基β分裂对溶剂极性敏感,脂质体环境会根据位置影响基因的行为.
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