Elucidating the pathway for arsenic methylation

These applications are controversial as they introduce soluble forms of arsenic into the environment.Despite, or possibly because of, its long-known toxicity, arsenic-containing potions and drugs have a history in medicine and quackery that continues into the 21st century.This pattern is general for other related elements, including selenium, which can exhibit both beneficial and deleterious effects.

elucidating the pathway for arsenic methylation-43elucidating the pathway for arsenic methylation-48elucidating the pathway for arsenic methylation-2

In an SN2 reaction, the positive charge on the SAM sulfur atom pulls the bonding electron from the carbon of the methyl group, which interacts with the arsenic lone pair to form an As−C bond, leaving SAH.

In humans, the major route of excretion of most arsenic compounds is via the urine.

Poultry and swine farms make heavy use of the organoarsenic compound roxarsone as an antibiotic in feed.

Some wood is treated with copper arsenates as a preservative.

Arsenic biochemistry refers to biochemical processes that can use arsenic or its compounds, such as arsenate.

Arsenic is a moderately abundant element in Earth's crust, and although many arsenic compounds are often considered highly toxic to most life, a wide variety of organoarsenic compounds are produced biologically and various organic and inorganic arsenic compounds are metabolized by numerous organisms.

With the uptake of arsenic within cells and the subsequent reactions that result in the production of reactive oxygen species (ROS), the Nrf2 unbinds and becomes active.

Keap1 has reactive thiol moieties that bind ROS or electrophilic arsenic species such as monomethylted arsenic (III) and induces the release of Nrf2 which then travels through the cytoplasm to the nucleus.

Arsenic (III) binding sites usually use thiol groups of cyseine residues.

The catalysis involves thiolates of Cys72, Cys174, and Cys224.

Inorganic arsenic and its compounds, upon entering the food chain, are progressively metabolised (detoxified) through a process of methylation.

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