Separation and identification of the selenium-sulfur amino acid S-(methylseleno) cysteine in intestinal epithelial cell homogenates by LC-ICP-MS and LC-ESI-MS after incubation with methylseleninic acid

Charlotte Gabel-Jensen, Kristoffer Lunoe, Kim Grimstrup Madsen, Jesper Bendix, Claus Cornett, Stefan Sturup, Helle Ruesz Hansen, Bente Gammelgaard

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18 Citations (Scopus)

Abstract

The metabolism of methylseleninic acid, MeSeA in the gastro-intestinal tract was studied by incubation of MeSeA with homogenized intestinal epithelial cells from pigs. The major selenium-containing metabolite was identified by analysis of the supernatant of the incubated cells by LC-ICP-MS. The identity of the compound was established by LC-ESI-MS/MS after purification by preparative chromatography. The metabolite appeared to be a selenium-sulfur amino acid, S-(methylseleno) cysteine (CH3Se-S-CH2CH(NH2)COOH). The selenium-sulfur ratio was confirmed to be 1: 1 by simultaneous monitoring of selenium and sulfur as the oxides by LC-ICP-MS. Analysis of a synthesized standard of S-( methylseleno) cysteine by LC-ESI-MS resulted in the same mass spectrum with the same fragmentation pattern as the isolated metabolite. The formation of this selenium compound did not require enzymatic systems but only the presence of cysteine. The presence of this selenium compound in mammalian cell models after addition of MeSeA has not previously been reported.

Original languageEnglish
Pages (from-to)727-732
Number of pages6
JournalJournal of Analytical Atomic Spectrometry
Volume23
Issue number5
Early online date28 Feb 2008
DOIs
Publication statusPublished - 2008

Keywords

  • plasma-mass spectrometry
  • in-vitro
  • metabolite
  • speciation
  • cancer
  • selenotrisulfides
  • glutathione
  • urine
  • yeast
  • vivo

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