Transition metal ions and selenite modulate the methylation of arsenite by the recombinant human arsenic (+3 oxidation state) methyltransferase (hAS3MT)

Journal of Inorganic Biochemistry
Xiaoli SongZhilin Wang

Abstract

This report demonstrates that transition metal ions and selenite affect the arsenite methylation by the recombinant human arsenic (+3 oxidation state) methyltransferase (hAS3MT) in vitro. Co(2+), Mn(2+), and Zn(2+) inhibited the arsenite methylation by hAS3MT in a concentration-dependent manner and the kinetics indicated Co(2+) and Mn(2+) to be mixed (competitive and non-competitive) inhibitors while Zn(2+) to be a competitive inhibitor. However, only a high concentration of Fe(2+) could restrain the methylation. UV-visible, CD and fluorescence spectroscopy were used to study the interactions between the metal ions above and hAS3MT. Further studies showed that neither superoxide anion nor hydrogen peroxide was involved in the transition metal ion or selenite inhibition of hAS3MT activity. The inhibition of arsenite methylating activity of hAS3MT by selenite was reversed by 2mM DTT (dithiothreitol) but neither by cysteine nor by beta-mercaptoethanol. Whereas, besides DTT, cysteine can also prevent the inhibition of hAS3MT activity by Co(2+), Mn(2+), and Zn(2+). Free Cys residues were involved in the interactions of transition metal ions or selenite with hAS3MT. It is proposed that the inhibitory effect of the ions (Co(2+), Mn(2+...Continue Reading

References

Aug 1, 1977·Environmental Health Perspectives·O A Levander
Aug 1, 1977·Environmental Health Perspectives·E A Crecelius
Jan 1, 1987·Mutagenesis·T Kuroki, T Matsushima
Mar 3, 1981·Biochemistry·J P Hennessey, W C Johnson
Jul 17, 1998·Biochemistry·Y Chen, M D Barkley
Jan 20, 2007·Science·Dmitri E FomenkoVadim N Gladyshev
Dec 25, 2007·Analytica Chimica Acta·Zdenka SlejkovecPeter Cernelc

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Citations

May 24, 2014·Environment International·Hong-Jie SunLena Q Ma
May 23, 2014·Journal of Biomaterials Science. Polymer Edition·Xiaoli SongPeizhi Zhu
Jul 8, 2017·Critical Reviews in Food Science and Nutrition·Carlos Jadán-PiedraVicenta Devesa
Sep 8, 2010·Journal of Environmental Monitoring : JEM·Julia BornhorstTanja Schwerdtle

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