Bromide peroxidase (, ''bromoperoxidase'', ''haloperoxidase (ambiguous)'', ''
eosinophil peroxidase'') is a family of
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
s with
systematic name
A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature.
A semisystematic name or semitrivi ...
''bromide:hydrogen-peroxide oxidoreductase''. These enzymes
catalyse the following
chemical reaction
A chemical reaction is a process that leads to the chemistry, chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an Gibbs free energy, ...
:
: HBr + H
2O
2 HOBr + H
2O
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
Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 recognized species within over 900 genera amidst ongoing taxonomic revisions. ...
'' and ''
Phaeophyta'') contain
vanadate (
vanadium bromoperoxidase). Otherwise vanadium is unusual cofactor in biology. 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
Muricidae is a large and varied taxonomic family of small to large predatory sea snails, marine gastropod mollusks, commonly known as murex snails or rock snails. With over 1,700 living species, the Muricidae represent almost 10% of the Neog ...
(was ''
Murex
''Murex'' is a genus of medium to large sized predatory tropical sea snails. These are carnivorous marine gastropod molluscs in the family Muricidae, commonly called "murexes" or "rock snails".Houart, R.; Gofas, S. (2010). Murex Linnaeus, 1 ...
'') spp. snails have a bromoperoxidase used to produce
Tyrian purple
Tyrian purple ( ''porphúra''; ), also known as royal purple, imperial purple, or imperial dye, is a reddish-purple natural dye. The name Tyrian refers to Tyre, Lebanon, once Phoenicia. It is secreted by several species of predatory sea snails ...
dye. The enzyme is very specific to bromide and physically stable, but has not been characterized as to its active site metal. , no specific gene has been assigned to such an enzyme in the snail genome. Such an activity is probably provided by symbiotic ''
Bacillus
''Bacillus'', from Latin "bacillus", meaning "little staff, wand", is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum ''Bacillota'', with 266 named species. The term is also used to describe the shape (rod) of other so-sh ...
'' bacteria instead. The identified enzyme belongs to the
alpha/beta hydrolase superfamily; a structure for a similar bromoperoxidase is available as . It runs on a
catalytic triad
A catalytic triad is a set of three coordinated amino acid residues that can be found in the active site of some enzymes. Catalytic triads are most commonly found in hydrolase and transferase enzymes (e.g. proteases, amidases, esterases, aminoac ...
of Ser 99, Asp 229 and His 258 and does not require metal cofactors.
Additional reading
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References
External links
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