Acta Chim. Sinica ›› 2018, Vol. 76 ›› Issue (10): 802-806.DOI: 10.6023/A18070297 Previous Articles     Next Articles

Article

常压下水自由基阳离子与双(2-羟乙基)二硫醚作用的质谱研究

高校飞, 何鹏, 陈焕文   

  1. 东华理工大学 江西省质谱科学与仪器重点实验室 南昌 330013
  • 收稿日期:2018-07-25 出版日期:2018-10-15 发布日期:2018-08-22
  • 通讯作者: 高校飞, 陈焕文 E-mail:sandy2005327@126.com;chw8868@gmail.com
  • 基金资助:

    项目受国家自然科学基金(No.21520102007)、江西省质谱科学与仪器重点实验室开放基金(No.JXMS201701)和东华理工大学博士启动基金(No.DHBK2017114)资助.

Study on the Interaction Between Water Radical Cations and Bis(2-hydroxyethyl) Disulfide at Ambient Temperature and Pressure Using Mass Spectrometry

Gao Xiao-Fei, He Peng, Chen Huanwen   

  1. Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China University of Technology, Nanchang 330013
  • Received:2018-07-25 Online:2018-10-15 Published:2018-08-22
  • Contact: 10.6023/A18070297 E-mail:sandy2005327@126.com;chw8868@gmail.com
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 21520102007), the Jiangxi Key Laboratory for Mass Spectrometry and Instru-mentation Open Foundation (No. JXMS201701) and the Research Fund of East China University of Technology (No. DHBK2017114).

In vivo, free radical damage of disulfide bonds in proteins affects the structure and function of proteins, and has an important relationship with cell aging. Therefore, studying the mechanism of the interaction between free radicals and disulfide bonds, and understanding the interaction process between free radicals and disulfide bonds, is important for the cleavage or proteciton of disulfide bond. In this paper, liquid-assisted surface desorption atmospheric pressure chemical ionization technology is adopted (LA-DAPCI), to construct a two-channel ion source device, obtaining high abundance water radical cations (H2O)n (n=2~4). Using linear ion trap mass spectrometer, combining with Density Functional Theory, the interaction process between (H2O)n and bis(2-hydroxyethyl) disulfide (HEDS) in mass spectrometer and thermodynamic process of the interaction were studied. The results indicated that (H2O)n interacted with HEDS, forming a radical complex (M+H2O) (m/z 172) without covalent bond, and H2O in complex (M+H2O) (m/z 172) is derived from (H2O)n, not from the H2O of sample solution. Furthermore, thermodynamic theoretical calculation results demonstrated that H on the β-hydroxyl group of HEDS structure forms a weak hydrogen bond with S in the form of an intramolecular five-membered ring. During the interaction process, (H2O)n preferentially binds to the hydroxyl group of HEDS, forming a radical complex (M+H2O), whose disulfide bond will be difficult to be cleaved. In conclusion, the β-hydroxyl group has a protective effect on the disulfide bond of HEDS during the interaction with water radical cations.

Key words: water radical cations, disulfide bonds, radical damage, atmospheric pressure chemical ionization