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dc.contributor.authorSarma, Diganta
dc.contributor.authorHajovsky, Heather
dc.contributor.authorKoen, Yakov M.
dc.contributor.authorGaleva, Nadezhda A.
dc.contributor.authorWilliams, Todd D.
dc.contributor.authorStaudinger, Jeffrey Leonard
dc.contributor.authorHanzlik, Robert P.
dc.date.accessioned2017-05-08T15:59:17Z
dc.date.available2017-05-08T15:59:17Z
dc.date.issued2012-09-17
dc.identifier.citationSarma, D., Hajovsky, H., Koen, Y. M., Galeva, N. A., Williams, T. D., Staudinger, J. L., & Hanzlik, R. P. (2012). Covalent Modification of Lipids and Proteins in Rat Hepatocytes, and In Vitro, by Thioacetamide Metabolites. Chemical Research in Toxicology, 25(9), 1868–1877. http://doi.org/10.1021/tx3001658en_US
dc.identifier.urihttp://hdl.handle.net/1808/23998
dc.descriptionThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Chemical Research in Toxicology, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/tx3001658en_US
dc.description.abstractThioacetamide (TA) is a well-known hepatotoxin in rats. Acute doses cause centrilobular necrosis and hyperbilirubinemia while chronic administration leads to biliary hyperplasia and cholangiocarcinoma. Its acute toxicity requires its oxidation to a stable S-oxide (TASO) that is oxidized further to a highly reactive S,S-dioxide (TASO2). To explore possible parallels between the metabolism, covalent binding and toxicity of TA and thiobenzamide (TB) we exposed freshly isolated rat hepatocytes to [14C]-TASO or [13C2D3]-TASO. TLC analysis of the cellular lipids showed a single major spot of radioactivity that mass spectral analysis showed to consist of N-acetimidoyl PE lipids having the same side chain composition as the PE fraction from untreated cells; no carbons or hydrogens from TASO were incorporated into the fatty acyl chains. Many cellular proteins contained N-acetyl- or N-acetimidoyl lysine residues in a 3:1 ratio (details to be reported separately). We also oxidized TASO with hydrogen peroxide in the presence of dipalmitoyl phosphatidylenthanolamine (DPPE) or lysozyme. Lysozyme was covalently modified at five of its six lysine side chains; only acetamide-type adducts were formed. DPPE in liposomes also gave only amide-type adducts, even when the reaction was carried out in tetrahydrofuran with only 10% water added. The exclusive formation of N-acetimidoyl PE in hepatocytes means that the concentration or activity of water must be extremely low in the region where TASO2 is formed, whereas at least some of the TASO2 can hydrolyze to acetylsulfinic acid before it reacts with cellular proteins. The requirement for two sequential oxidations to produce a reactive metabolite is unusual, but it is even more unusual that a reactive metabolite would react with water to form a new compound that retains a high degree of chemical reactivity toward biological nucleophiles. The possible contribution of lipid modification to the hepatotoxicity of TA/TASO remains to be determined.en_US
dc.publisherACSen_US
dc.rightsCopyright © 2012 American Chemical Societyen_US
dc.titleCovalent Modification of Lipids and Proteins in Rat Hepatocytes, and In Vitro, by Thioacetamide Metabolitesen_US
dc.typeArticleen_US
kusw.kuauthorSarma, Diganta
kusw.kuauthorHajovsky, Heather
kusw.kuauthorKoen, Yakov M.
kusw.kuauthorHanzlik, Robert P.
kusw.kuauthorGaleva, Nadezhda A.
kusw.kuauthorWilliams, Todd D.
kusw.kuauthorStaudinger, Jeffrey L.
kusw.kudepartmentMedicinal Chemistryen_US
kusw.kudepartmentMass Spectrometry Laboratoryen_US
kusw.kudepartmentDepartment of Pharmacology & Toxicologyen_US
dc.identifier.doi10.1021/tx3001658en_US
kusw.oaversionScholarly/refereed, author accepted manuscripten_US
kusw.oapolicyThis item meets KU Open Access policy criteria.en_US
dc.identifier.pmidPMC3444623en_US
dc.rights.accessrightsopenAccess


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