Observation of the seleno bis-(S-glutathionyl) arsinium anion in rat bile

Graham N. George, Jürgen Gailer, Olena Ponomarenko, Paul F. La Porte, Karen Strait, Mohammad Alauddin, Habibul Ahsan, Selim Ahmed, Julian Spallholz, Ingrid J. Pickering

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Certain arsenic and selenium compounds show a remarkable mutual cancelation of toxicities, where a lethal dose of one can be voided by an equimolar and otherwise lethal dose of the other. It is now well established that the molecular basis of this antagonism is the formation and biliary excretion of seleno bis-(S-glutathionyl) arsinium anion [(GS)2AsSe]-. Previous work has definitively demonstrated the presence of [(GS)2AsSe]- in rabbit bile, but only in the presence of other arsenic and selenium species. Rabbits have a gall bladder, which concentrates bile and lowers its pH; it seems likely that this may be responsible for the breakdown of biliary [(GS)2AsSe]-. Since rats have no gall bladder, the bile proceeds directly through the bile duct from the hepatobiliary tree. In the present work we have shown that the primary product of biliary co-excretion of arsenic and selenium in rats is [(GS)2AsSe]-, with essentially 100% of the arsenic and selenium present as this species. The chemical plausibility of the X-ray absorption spectroscopy-derived structural conclusions of this novel arsenic and selenium co-excretion product is supported by density functional theory calculations. These results establish the biomolecular basis to further explore the use of selenium dietary supplements as a possible palliative for chronic low-level arsenic poisoning of human populations.

Original languageEnglish
Pages (from-to)24-29
Number of pages6
JournalJournal of Inorganic Biochemistry
Volume158
DOIs
StatePublished - May 1 2016

Keywords

  • Arsenic-selenium antagonism
  • DFT
  • EXAFS
  • X-ray absorption spectroscopy

Fingerprint Dive into the research topics of 'Observation of the seleno bis-(S-glutathionyl) arsinium anion in rat bile'. Together they form a unique fingerprint.

  • Cite this

    George, G. N., Gailer, J., Ponomarenko, O., La Porte, P. F., Strait, K., Alauddin, M., Ahsan, H., Ahmed, S., Spallholz, J., & Pickering, I. J. (2016). Observation of the seleno bis-(S-glutathionyl) arsinium anion in rat bile. Journal of Inorganic Biochemistry, 158, 24-29. https://doi.org/10.1016/j.jinorgbio.2016.01.022