Iodoacetate

Iodoacetate refers to the salts or esters derived from iodoacetic acid. The most commonly used forms are sodium iodoacetate and potassium iodoacetate. These compounds are small, reactive organoiodine reagents that act as alkylating agents, with the iodine atom rendering the adjacent methylene group highly susceptible to nucleophilic attack.

Iodoacetate compounds are typically prepared from iodoacetic acid, which in turn can be generated by halogenation of glycolic derivatives followed by oxidation and neutralization to form the desired salt. In solution they are relatively water-soluble and are reactive with nucleophiles, particularly thiolate groups on cysteine residues. This reactivity underpins their biochemical utility but also requires careful handling due to potential hazards.

In biochemistry and pharmacology, iodoacetate is used as an irreversible alkylating agent to inhibit thiol-containing enzymes. A classic application is the inactivation of glyceraldehyde-3-phosphate dehydrogenase, which makes iodoacetate a tool for studying glycolytic pathways and enzyme mechanism. It is also used to derivatize free sulfhydryl groups in proteins for analytical labeling, though iodoacetamide is more commonly employed for that purpose due to different reactivity and stability.

Safety and handling are important considerations. Iodoacetate is an irritant and is hazardous if inhaled, ingested, or absorbed through the skin. It can cause severe irritation and is toxic to living tissues. Work should be conducted in a fume hood with appropriate personal protective equipment, and solutions should be prepared and stored away from reducing agents and moisture.

See also: iodoacetamide, iodoacetic acid.