|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 18.104.22.168
Enzymes and Genes:
|Curvularia inaequalis :||chloride peroxygenase
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: chloride peroxidase
Enzyme Commission Synonyms: chloroperoxidase, CPO, vanadium haloperoxidase
Standard Gibbs Free Energy (ΔrG'° in kcal/mol): -60.948753 [Latendresse13]
Enzyme Commission Summary:
Brings about the chlorination of a range of organic molecules, forming stable C-Cl bonds. Can also act on Br- and I-.
Enzymes of this type are either heme-thiolate proteins, or contain vanadate. A secreted enzyme produced by the ascomycetous fungus Caldariomyces (Leptoxyphium) fumago is an example of the heme-thiolate type. It catalyses the production of hypochlorous acid by transferring one oxygen atom from H2O2 to chloride, as described in the following reaction:
At a separate site it catalyses the chlorination of activated aliphatic and aromatic substrates, via HClO and derived chlorine species, as described in the following reaction:
Also oxidizes bromide and iodide. In the absence of halides, it shows peroxidase (e.g. phenol oxidation) and peroxygenase activities. The latter inserts oxygen from H2O2 into, for example, styrene (side chain epoxidation) and toluene (benzylic hydroxylation), however, these activities are less pronounced than its activity with halides. Has little activity with non-activated substrates such as aromatic rings, ethers or saturated alkanes. The chlorinating peroxidase produced by ascomycetous fungi (e.g. Curvularia inaequalis) is an example of a vanadium chloroperoxidase, and is related to bromide peroxidase (EC 22.214.171.124). It contains vanadate and oxidizes chloride, bromide and iodide into hypohalous acids. In the absence of halides, it peroxygenates organic sulfides and oxidizes 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) but no phenols.
Unification Links: KEGG:R00052
Relationship Links: BRENDA:EC:126.96.36.199 , ENZYME:EC:188.8.131.52 , IUBMB-ExplorEnz:EC:184.108.40.206 , UniProt:RELATED-TO:P04963 , UniProt:RELATED-TO:P49053 , UniProt:RELATED-TO:P49323 , UniProt:RELATED-TO:Q53540
Kuhnel06: Kuhnel K, Blankenfeldt W, Terner J, Schlichting I (2006). "Crystal structures of chloroperoxidase with its bound substrates and complexed with formate, acetate, and nitrate." J Biol Chem 281(33);23990-8. PMID: 16790441
Murali06: Murali Manoj K (2006). "Chlorinations catalyzed by chloroperoxidase occur via diffusible intermediate(s) and the reaction components play multiple roles in the overall process." Biochim Biophys Acta 1764(8);1325-39. PMID: 16870515
Sundaramoorthy95: Sundaramoorthy M, Terner J, Poulos TL (1995). "The crystal structure of chloroperoxidase: a heme peroxidase--cytochrome P450 functional hybrid." Structure 3(12);1367-77. PMID: 8747463
tenBrink00: ten Brink HB, Dekker HL, Schoemaker HE, Wever R (2000). "Oxidation reactions catalyzed by vanadium chloroperoxidase from Curvularia inaequalis." J Inorg Biochem 80(1-2);91-8. PMID: 10885468
tenBrink98: ten Brink HB, Tuynman A, Dekker HL, Hemrika W, Izumi Y, Oshiro T, Schoemaker HE, Wever R (1998). "Enantioselective Sulfoxidation Catalyzed by Vanadium Haloperoxidases." Inorg Chem 37(26);6780-6784. PMID: 11670813
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