Английская Википедия:Bromide peroxidase

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Шаблон:Short description Шаблон:Infobox enzyme

Bromide peroxidase (Шаблон:EC number, bromoperoxidase, haloperoxidase (ambiguous), eosinophil peroxidase) is a family of enzymes with systematic name bromide:hydrogen-peroxide oxidoreductase. These enzymes catalyse the following chemical reaction:[1][2][3]

HBr + H2O2 <math>\rightleftharpoons</math> HOBr + H2O

The HOBr is a potent brominating agent. The many organobromine compounds observed in marine environments are the products of reaction with this oxidized form of bromine.

Bromo peroxidases of red and brown marine algae (Rhodophyta and Phaeophyta) contain vanadate (vanadium bromoperoxidase). Otherwise vanadium is unusual cofactor in biology.[4] By virtue of this family of enzymes, a variety of brominated natural products have been isolated from marine sources.

Related chloroperoxidase enzymes effect chlorination. In the nomenclature of haloperoxidase, bromoperoxidases classically are unable to oxidize chloride at all. For example, eosinophil peroxidase appears to prefer bromide over chloride, yet is not considered a bromoperoxidase because it is able to use chloride.

Muricidae (was Murex) spp. snails have a bromoperoxidase used to produce Tyrian purple dye. The enzyme is very specific to bromide and physically stable, but has not been characterized as to its active site metal. Шаблон:As of, no specific gene has been assigned to such an enzyme in the snail genome.[5] Such an activity is probably provided by symbiotic Bacillus bacteria instead.[6] The identified enzyme belongs to the alpha/beta hydrolase superfamily; a structure for a similar bromoperoxidase is available as Шаблон:PDB. It runs on a catalytic triad of Ser 99, Asp 229 and His 258 and does not require metal cofactors.[7]

Additional reading

References

Шаблон:Reflist

External links

Шаблон:Peroxidases Шаблон:Enzymes Шаблон:Portal bar

  1. Шаблон:Cite journal
  2. Шаблон:Cite journal
  3. Шаблон:Cite journal
  4. Butler, A., "Vanadium haloperoxidases", Current Opinion in Chemical Biology, 1998, 2, 279-285.
  5. Шаблон:Cite journal
  6. Шаблон:Cite journal Genbank AKQ77155.1.
  7. Шаблон:Cite web