模型和二硫化物的结构显著影响它们的反应性和用单片氧形成的产品
Qing Gao1, Katarzyna Grzyb2, Luke F Gamon1
1Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, 2200, Denmark.
Free radical biology & medicine
|August 26, 2023
概括
单片氧选择性氧化二硫化物键,导致不同的反应速率和产物. 这种对二硫化物的选择性修饰,包括蛋白质中的二硫化物,可以影响蛋白质的结构和功能.
科学领域:
- 生物化学 生物化学
- 化学动力学 化学动力学
- 摄影化学的使用
背景情况:
- 二硫化物键对于蛋白质的结构和功能至关重要.
- 二硫化物的氧化会导致蛋白质的完整性丧失.
- 之前的研究表明,二硫化物与低酸的氧化率可变.
研究的目的:
- 通过单一氧气 (1O2) 对二硫化物氧化的动力学进行研究.
- 为了确定单点氧是否可以选择性氧化不同的二硫化物键.
- 阐明二硫化物光氧化反应的反应机制和产物.
主要方法:
- 通过时间解析的1270nm光学监测单点氧 (1O2) 去除.
- 使用液态染色体质谱法 (LC-MS) 分析二硫化物损失和产品形成.
- 在D2O和H2O缓冲器中比较反应动力学,以评估溶剂效应.
主要成果:
- 观察到不同二硫化物单点氧火速常数 (k<0xE1><0xB5><0xA1>) 的广泛变化 (∼103倍).
- 检测到单氧和二氧化物产物,支持1O2在二硫化物修饰中的作用.
- 在D2O缓冲器中发现产品含量升高,与溶剂对1O2寿命的影响一致.
- 提出了一种反应机制,涉及到一个zwitterionic中间体和随后的异构化或反应.
结论:
- 单片氧对不同的二硫化物键具有选择性反应性.
- 反应活性的变化归因于由单双电子稳定兹维特里昂.
- 选择性修改和蛋白质二硫化物1O2的裂变是可能的,可能会影响蛋白质的结构和功能.
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