Arsenite methyltransferase explained

Arsenite methyltransferase
Ec Number:	2.1.1.137
Cas Number:	167140-41-2

Arsenite methyltransferase (S-adenosyl-L-methionine:arsenic(III) methyltransferase, S-adenosyl-L-methionine:methylarsonite As-methyltransferase, methylarsonite methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:arsenite As-methyltransferase.^{[1] [2] [3] [4] [5]} This enzyme catalyses the following chemical reaction

\rightleftharpoons S-adenosyl-L-homocysteine + methylarsonate

(2) S-adenosyl-L-methionine + methylarsonite

\rightleftharpoons S-adenosyl-L-homocysteine + dimethylarsinate

An enzyme of the biotransformation pathway that forms dimethylarsinate from inorganic arsenite and arsenate.

Notes and References

1. Zakharyan RA, Aposhian HV . Enzymatic reduction of arsenic compounds in mammalian systems: the rate-limiting enzyme of rabbit liver arsenic biotransformation is MMA(V) reductase . Chemical Research in Toxicology . 12 . 12 . 1278–83 . December 1999 . 10604879 . 10.1021/tx9901231 .
2. Zakharyan RA, Ayala-Fierro F, Cullen WR, Carter DM, Aposhian HV . Enzymatic methylation of arsenic compounds. VII. Monomethylarsonous acid (MMAIII) is the substrate for MMA methyltransferase of rabbit liver and human hepatocytes . Toxicology and Applied Pharmacology . 158 . 1 . 9–15 . July 1999 . 10387927 . 10.1006/taap.1999.8687 .
3. Zakharyan RA, Wildfang E, Aposhian HV . Enzymatic methylation of arsenic compounds. III. The marmoset and tamarin, but not the rhesus, monkeys are deficient in methyltransferases that methylate inorganic arsenic . Toxicology and Applied Pharmacology . 140 . 1 . 77–84 . September 1996 . 8806872 . 10.1006/taap.1996.0199 .
4. Zakharyan R, Wu Y, Bogdan GM, Aposhian HV . Enzymatic methylation of arsenic compounds: assay, partial purification, and properties of arsenite methyltransferase and monomethylarsonic acid methyltransferase of rabbit liver . Chemical Research in Toxicology . 8 . 8 . 1029–38 . December 1995 . 8605285 . 10.1021/tx00050a006 .
5. Lin S, Shi Q, Nix FB, Styblo M, Beck MA, Herbin-Davis KM, Hall LL, Simeonsson JB, Thomas DJ . A novel S-adenosyl-L-methionine:arsenic(III) methyltransferase from rat liver cytosol . The Journal of Biological Chemistry . 277 . 13 . 10795–803 . March 2002 . 11790780 . 10.1074/jbc.M110246200 . free .