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Study on the intermediate ions formed by glutathione peroxidase mimic 2,2'-ditellurobis(2-deoxy-β-cyclodextrin) by electrospray ionization mass spectrometry

Authors

  • Aiquan Jiao,

    1. The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
    2. School of Food Science and Technology, Jiangnan University, Wuxi, China
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  • Na Yang,

    1. The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
    2. School of Food Science and Technology, Jiangnan University, Wuxi, China
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  • Xueming Xu,

    1. The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
    2. School of Food Science and Technology, Jiangnan University, Wuxi, China
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  • Zhengyu Jin

    Corresponding author
    1. The State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
    • School of Food Science and Technology, Jiangnan University, Wuxi, China
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Z. Y. Jin, The State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.

E-mail: jinlab2008@yahoo.com

Abstract

RATIONALE

2,2'-Ditellurobis(2-deoxy-β-cyclodextrin) (2-TeCD) is one of the most well-known glutathione peroxidase (GPx) mimics. However, because the critical reaction intermediates had not previously been isolated or directly detected due to its short lifetime, the catalytic mechanism of 2-TeCD is not very clear and further experiments are needed to characterize each of the intermediates in the catalytic cycle.

METHODS

Using electrospray ionization mass (and tandem) spectrometry (ESI-MS and ESI-MS/MS) experiments, the decomposition of hydrogen peroxide at the expense of glutathione (GSH) catalyzed by 2-TeCD was monitored on-line.

RESULTS

The key intermediates were successfully intercepted and structurally characterized for the first time by coupling a microreactor on-line to the ESI ion source, which permitted the fast screening of intermediates directly from solution.

CONCLUSIONS

The catalytic mechanism of 2-TeCD catalysis has been elaborated based on mass spectrometric data and exerted its peroxidase activity via tellurol, tellurenic acid, and tellurosulfide, in analogy with natural GPX. Copyright © 2012 John Wiley & Sons, Ltd.

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