Iodoacetic acid
| Iodoacetic acid | |
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| Identifiers | |
| CAS number | 64-69-7  |
| PubChem | 5240 |
| ChemSpider | 5050 |
| ChEMBL | CHEMBL376280 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C2H3IO2 |
| Molar mass | 185.95 g mol−1 |
| Melting point |
81 °C, 354 K, 178 °F |
| Boiling point |
208 °C, 481 K, 406 °F |
| Hazards | |
| MSDS | Oxford MSDS |
| EU classification | Toxic (T); Corrosive (C) |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Iodoacetic acid is a derivative of acetic acid. It is a toxic compound, because, like many alkyl halides, it is an alkylating agent. It reacts with cysteine residues in proteins. It is often used to modify SH-groups to prevent the re-formation of disulfide bonds after the reduction of cystine residues to cysteine during protein sequencing.
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[edit] Peptidase inhibitor
Iodoacetate 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 amide derivative, iodoacetamide, iodoacetate reacts substantially faster. 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 activity of iodoacetate.[1]
[edit] Possible cancer therapy
Several studies have shown iodoacetate has anti-tumor effects. In 2002 Dr. Fawzia Fahim showed that "a single IAA treatment of tumor-bearing mice significantly increased the levels of plasma lactate dehydrogenase (LDH) activity, while it also significantly decreased the levels of plasma glucose and liver total protein, RNA and DNA, compared to normal controls."[2] In 1975 Melvin S. Rhein, Joyce A. Filppi and Victor S. Moore showed that iodoacetate improved the immune response of bone marrow.[3] In 1966 Charles A. Apffel, Barry G. Arnason & John H. Peters showed anti-tumor activity for iodoacetate.[4]
[edit] See also
[edit] References
- ^ 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.
- ^ Fawzia A Fahim, Amr Y Esmat, Essam A Mady and Emad K Ibrahim (2003). "Antitumor Activities of Iodoacetate and Dimethylsulphoxide Against Solid Ehrlich Carcinoma Growth in Mice". Biol. Res. 36 (2): 253–262. PMID 14513720.
- ^ Melvin S. Rhein, Joyce A. Filppi and Victor S. Moore (1975). "Effect of Iodoacetate on the Bone Marrow Immunocompetence of AKR Mice.". Cancer Research 35 (6): 1514–1519. PMID 1093673.
- ^ Charles A. Apffel, Barry G. Arnason & John H. Peters (1966). "Induction of tumour immunity with tumour cells treated with iodoacetate.". Nature 209 (5021): 694–696. doi:10.1038/209694a0. PMID 5922128.
[edit] Further reading
- A. K. Knap and R. F. Pratt (1991). "Inactivation of the RTEM-1 cysteine beta-lactamase by iodoacetate. The nature of active-site functional groups and comparisons with the native enzyme". Biochem. J. 273: 85–91. PMID 1989590. http://www.biochemj.org/bj/273/bj2730085.htm.
- Dickens F (1933). "Interaction of halogenacetates and SH compounds. The reaction of halogenacetic acids with glutathione and cysteine. The mechanism of iodoacetate poisoning of glyoxalase.". Biochem. J. 27 (4): 1141–1151. PMC 1253000. PMID 16745202. http://www.biochemj.org/bj/027/bj0271141.htm.
[edit] External links
- The MEROPS online database for peptidases and their inhibitors: Iodoacetate
