Iodoacetamide

Iodoacetamide
Names
	IUPAC name Iodoacetamide
Identifiers
CAS Number	144-48-9 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL276727 ;
ChemSpider	3596 ;
ECHA InfoCard	100.005.119
EC Number	205-630-1;
PubChem CID	3727;
RTECS number	AC4200000;
UNII	ZRH8M27S79 ;
CompTox Dashboard (EPA)	DTXSID9020742 ;
	InChI InChI=1S/C2H4INO/c3-1-2(4)5/h1H2,(H2,4,5) Key: PGLTVOMIXTUURA-UHFFFAOYSA-N ; InChI=1/C2H4INO/c3-1-2(4)5/h1H2,(H2,4,5) Key: PGLTVOMIXTUURA-UHFFFAOYAE;
	SMILES C(C(=O)N)I;
Properties
Chemical formula	C2H4INO
Molar mass	184.964 g·mol−1
Appearance	white crystals (yellow colouration indicates the presence of iodine)
Melting point	94 °C (201 °F; 367 K)
Hazards
NFPA 704 (fire diamond)	3 0 1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

2-Iodoacetamide is an alkylating agent used for peptide mapping purposes. Its actions are similar to those of iodoacetate. It is commonly used to bind covalently with the thiol group of cysteine so the protein cannot form disulfide bonds.^[1]^[2] Also used in ubiquitin studies as an inhibitor of deubiquitinase enzymes (DUBs) because it alkylates the cysteine residues at the DUB active site.

Peptidase inhibitor

Iodoacetamide is an irreversible inhibitor of all cysteine peptidases, with the mechanism of inhibition occurring from alkylation of the catalytic cysteine residue (see schematic). In comparison with its acid derivative, iodoacetate, iodoacetamide reacts substantially more quickly. This observation appears contradictory to standard chemical reactivity, however the presence of a favourable interaction between the positive imidazolium ion of the catalytic histidine and the negatively charged carboxyl-group of the iodoacetate is the reason for the increased relative activity of iodoacetamide.^[3]

References

^ Smythe CV (1936). "The reactions of Iodoacetate and of Iodoacetamide with various Sulfhydryl groups, with Urease, and with Yeast preparations". J. Biol. Chem. 114 (3): 601–12.
^ Anson ML (1940). "The reactions of Iodine and Iodoacetamide with native Egg Albumin". J. Gen. Physiol. 23 (3): 321–31. doi:10.1085/jgp.23.3.321. PMC 2237930. PMID 19873158.
^ Polgar, L (1979). "Deuterium isotope effects on papain acylation. Evidence for lack of general base catalysis and for enzyme-leaving group. interaction". Eur. J. Biochem. 98 (2): 369–374. doi:10.1111/j.1432-1033.1979.tb13196.x. PMID 488108.

External links

The MEROPS online database for peptidases and their inhibitors: Iodoacetamide

[1] Smythe CV (1936). "The reactions of Iodoacetate and of Iodoacetamide with various Sulfhydryl groups, with Urease, and with Yeast preparations". J. Biol. Chem. 114 (3): 601–12.

[2] Anson ML (1940). "The reactions of Iodine and Iodoacetamide with native Egg Albumin". J. Gen. Physiol. 23 (3): 321–31. doi:10.1085/jgp.23.3.321. PMC 2237930. PMID 19873158.

[3] Polgar, L (1979). "Deuterium isotope effects on papain acylation. Evidence for lack of general base catalysis and for enzyme-leaving group. interaction". Eur. J. Biochem. 98 (2): 369–374. doi:10.1111/j.1432-1033.1979.tb13196.x. PMID 488108.

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