Jiao A, Yang N, Xu X, Jin Z. Study on the intermediate ions formed by glutathione peroxidase mimic 2,2'-ditellurobis(2-deoxy-β-cyclodextrin) by electrospray ionization mass spectrometry.
RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013;
27:319-324. [PMID:
23239379 DOI:
10.1002/rcm.6455]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 10/18/2012] [Accepted: 10/25/2012] [Indexed: 06/01/2023]
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.
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