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Ozone Oxidizes Glutathione to a Sulfonic Acid

Enami, Shinichi and Hoffmann, M. R. and Colussi, A. J. (2009) Ozone Oxidizes Glutathione to a Sulfonic Acid. Chemical Research in Toxicology, 22 (1). pp. 35-40. ISSN 0893-228X. https://resolver.caltech.edu/CaltechAUTHORS:ENAcrt09

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Abstract

Biosurfaces are universally covered with fluid microfilms containing reduced glutathione (GSH) and other antioxidants whose putative roles include the detoxification of ambient ozone (O_3). It is generally believed that O_3 accepts an electron from the thiolate GS^(2-) function [pK_a(GS^-) = 8.8] of GSH to produce thiyl GS^(•-) radicals en route to the disulfide GSSG. Here, we report novel electrospray mass spectrometry experiments showing that sulfonates (GSO_3^-/GSO_3^(2-)), not GSSG, are the exclusive final products on the surface of aqueous GSH microdroplets exposed to dilute O_3(g) for ~1 ms. The higher reactivity of the thiolate GS^(2-) toward O_3(g) over the thiol GS^- is kinetically resolved in this time frame due to slow GS^- acid dissociation. However, our experiments also show that O_3 will be largely scavenged by the more reactive ascorbate coantioxidant in typical interfacial biofilms. The presence of GSSG and the absence of GSO_3^-/GSO_3^(2-) in extracellular lining fluids are therefore evidence of GSH oxidation by species other than O_3.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/tx800298jDOIArticle
ORCID:
AuthorORCID
Enami, Shinichi0000-0002-2790-7361
Hoffmann, M. R.0000-0001-6495-1946
Colussi, A. J.0000-0002-3400-4101
Additional Information:© 2009 American Chemical Society. Received August 7, 2008. Publication Date (Web): 12 December 2008. Acknowledgment. This project was financially supported by the National Science Foundation (ATM-0534990). S.E. is grateful to the Japan Society for the Promotion of Science Research Fellowship for Young Scientists.
Funders:
Funding AgencyGrant Number
NSFATM-0534990
Japan Society for the Promotion of Science (JSPS)UNSPECIFIED
Issue or Number:1
Record Number:CaltechAUTHORS:ENAcrt09
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:ENAcrt09
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13616
Collection:CaltechAUTHORS
Deposited By: Arun Sannuti
Deposited On:13 Aug 2009 23:35
Last Modified:03 Mar 2020 13:01

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