PMID- 20129672
OWN - NLM
STAT- MEDLINE
DCOM- 20100607
LR  - 20131121
IS  - 1873-3344 (Electronic)
IS  - 0162-0134 (Linking)
VI  - 104
IP  - 5
DP  - 2010 May
TI  - Transition metal ions and selenite modulate the methylation of arsenite by the 
      recombinant human arsenic (+3 oxidation state) methyltransferase (hAS3MT).
PG  - 541-50
LID - 10.1016/j.jinorgbio.2010.01.005 [doi]
AB  - 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+), and Zn(2+)) or selenite on hAS3MT activity might be via the interactions 
      of them with free Cys residues in hAS3MT to form inactive protein adducts.
FAU - Song, Xiaoli
AU  - Song X
AD  - State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical 
      Engineering, Nanjing University, Nanjing 210093, PR China.
FAU - Geng, Zhirong
AU  - Geng Z
FAU - Li, Chengying
AU  - Li C
FAU - Hu, Xin
AU  - Hu X
FAU - Wang, Zhilin
AU  - Wang Z
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100118
PL  - United States
TA  - J Inorg Biochem
JT  - Journal of inorganic biochemistry
JID - 7905788
RN  - 0 (Ions)
RN  - 0 (Metals)
RN  - 0 (Sulfhydryl Compounds)
RN  - 3G0H8C9362 (Cobalt)
RN  - 42Z2K6ZL8P (Manganese)
RN  - E1UOL152H7 (Iron)
RN  - EC 2.1.1.- (Methyltransferases)
RN  - EC 2.1.1.137 (AS3MT protein, human)
RN  - HIW548RQ3W (Sodium Selenite)
RN  - J41CSQ7QDS (Zinc)
RN  - N712M78A8G (Arsenic)
SB  - IM
MH  - Animals
MH  - Arsenic/*chemistry/metabolism
MH  - Cobalt/chemistry/metabolism
MH  - Humans
MH  - Ions/*chemistry
MH  - Iron/chemistry/metabolism
MH  - Manganese/chemistry/metabolism
MH  - Metals/*chemistry/metabolism
MH  - *Methyltransferases/chemistry/metabolism
MH  - Models, Molecular
MH  - Oxidation-Reduction
MH  - Protein Structure, Secondary
MH  - Protein Structure, Tertiary
MH  - Sodium Selenite/*chemistry/metabolism
MH  - Sulfhydryl Compounds/chemistry
MH  - Zinc/chemistry/metabolism
EDAT- 2010/02/05 06:00
MHDA- 2010/06/09 06:00
CRDT- 2010/02/05 06:00
PHST- 2009/04/29 00:00 [received]
PHST- 2010/01/08 00:00 [revised]
PHST- 2010/01/11 00:00 [accepted]
PHST- 2010/02/05 06:00 [entrez]
PHST- 2010/02/05 06:00 [pubmed]
PHST- 2010/06/09 06:00 [medline]
AID - S0162-0134(10)00009-7 [pii]
AID - 10.1016/j.jinorgbio.2010.01.005 [doi]
PST - ppublish
SO  - J Inorg Biochem. 2010 May;104(5):541-50. doi: 10.1016/j.jinorgbio.2010.01.005. 
      Epub 2010 Jan 18.