chloride peroxidase
{{Infobox enzyme
| Name = Chloride peroxidase
| EC_number = 1.11.1.10
| CAS_number = 9055-20-3
| GO_code =
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Chloride peroxidase ({{EC number|1.11.1.10}}) is a family of enzymes that catalyzes the chlorination of organic compounds. This enzyme combines the inorganic substrates chloride and hydrogen peroxide to produce the equivalent of Cl+, which replaces a proton in hydrocarbon substrate:
:R-H + Cl− + H2O2 + H+ → R-Cl + 2 H2O
In fact the source of "Cl+" is hypochlorous acid (HOCl).{{cite journal|last1=Hofrichter|first1=M.|last2=Ullrich|first2=R.|last3=Pecyna|first3=Marek J.|first4=Christiane |last4= Liers|first5=Taina |last5=Lundell|journal=Appl Microbiol Biotechnol|year=2010|volume=87|doi=10.1007/s00253-010-2633-0| pages= 871–897 | title=New and classic families of secreted fungal heme peroxidases|issue=3|pmid=20495915|s2cid=24417282}} Many organochlorine compounds are biosynthesized in this way.
This enzyme belongs to the family of oxidoreductases, specifically those acting on a peroxide as acceptors (peroxidases). The systematic name of this enzyme class is chloride:hydrogen-peroxide oxidoreductase. This enzyme is also called chloroperoxidase. It employs one cofactor which may be either heme or vanadium.{{Cite journal|journal = Natural Product Reports|year = 2004|volume = 21|issue = 1|pmid = 15039842|doi = 10.1039/b302337k|title = The role of vanadium bromoperoxidase in the biosynthesis of halogenated marine natural products|first = Alison|last = Butler|author2=Carter-Franklin, Jayme N.|pages = 180–8}} (this paper also discussed chloroperoxidases.
The heme-containing chloroperoxidase (CPO) exhibits peroxidase, catalase and cytochrome P450-like activities in addition to catalyzing halogenation reactions.{{cite journal |doi=10.1016/S0969-2126(01)00274-X |vauthors=Poulos TL, Sundaramoorthy M, Terner J |title=The crystal structure of chloroperoxidase: a heme peroxidase--cytochrome P450 functional hybrid |journal=Structure |volume=3 |issue=12 |pages=1367–1377 |year=1995 |pmid=8747463|doi-access=free }} Despite functional similarities with other heme enzymes, the structure of CPO is unique, which folds into a tertiary structure dominated by eight helical segments. The catalytic acid base, required to cleave the peroxide O-O bond, is glutamic acid rather than histidine as in horseradish peroxidase.
Structural studies
As of late 2007, 30 structures have been solved for this class of enzymes, with PDB accession codes {{PDB link|1A7U}}, {{PDB link|1A88}}, {{PDB link|1A8Q}}, {{PDB link|1A8S}}, {{PDB link|1A8U}}, {{PDB link|1BRT}}, {{PDB link|1CPO}}, {{PDB link|1IDQ}}, {{PDB link|1IDU}}, {{PDB link|1QHB}}, {{PDB link|1QI9}}, {{PDB link|1VNC}}, {{PDB link|1VNE}}, {{PDB link|1VNF}}, {{PDB link|1VNG}}, {{PDB link|1VNH}}, {{PDB link|1VNI}}, {{PDB link|1VNS}}, {{PDB link|2CIV}}, {{PDB link|2CIW}}, {{PDB link|2CIX}}, {{PDB link|2CIY}}, {{PDB link|2CIZ}}, {{PDB link|2CJ0}}, {{PDB link|2CJ1}}, {{PDB link|2CJ2}}, {{PDB link|2CPO}}, {{PDB link|2J18}}, {{PDB link|2J19}}, and {{PDB link|2J5M}}.
References
{{reflist|1}}
Further reading
- {{cite journal |vauthors=Hager LP, Hollenberg PF, Rand-Meir T, Chiang R, Doubek D | year = 1975 | title = Chemistry of peroxidase intermediates | journal = Ann. N. Y. Acad. Sci. | volume = 244 | issue = 1 | pages = 80–93 | pmid = 1056179 | doi = 10.1111/j.1749-6632.1975.tb41524.x | bibcode = 1975NYASA.244...80H | s2cid = 27336177 }}
- {{cite journal |vauthors=Morris DR, Hager LP | year = 1966 | title = Chloroperoxidase. I. Isolation and properties of the crystalline glycoprotein | journal = J. Biol. Chem. | volume = 241 | pages = 1763–8 | pmid = 5949836 | issue = 8 | doi = 10.1016/S0021-9258(18)96701-3 | doi-access = free }}
- {{cite journal |vauthors=Theiler R, Cook JC, Hager LP, Siuda JF | year = 1978 | title = Halohydrocarbon synthesis by homoperoxidase | journal = Science | volume = 202 | pages = 1094–1096 | doi = 10.1126/science.202.4372.1094 | pmid = 17777960 | issue = 4372 | bibcode = 1978Sci...202.1094T | s2cid = 21448823 }}
{{Peroxidases}}
{{Enzymes}}
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