In
enzymology, a trypanothione-disulfide reductase () is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
that
catalyzes the
chemical reaction
A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...
:trypanothione + NADP
+ trypanothione disulfide + NADPH + H
+
Thus, the two
substrates of this enzyme are
trypanothione
Trypanothione is an unusual form of glutathione containing two molecules of glutathione joined by a spermidine ( polyamine) linker. It is found in parasitic protozoa such as leishmania and trypanosomes. These protozoal parasites are the cause of ...
and
NADP+, whereas its 3
products
Product may refer to:
Business
* Product (business), an item that serves as a solution to a specific consumer problem.
* Product (project management), a deliverable or set of deliverables that contribute to a business solution
Mathematics
* Produ ...
are
trypanothione disulfide,
NADPH, and
H+.
This enzyme belongs to the family of
oxidoreductase
In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually u ...
s, specifically those acting on a sulfur group of donors with NAD+ or NADP+ as acceptor. The
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 semitrivial ...
of this enzyme class is trypanothione:NADP+ oxidoreductase. Other names in common use include trypanothione reductase, and NADPH2:trypanothione oxidoreductase. It employs one
cofactor,
FAD
A fad or trend is any form of collective behavior that develops within a culture, a generation or social group in which a group of people enthusiastically follow an impulse for a short period.
Fads are objects or behaviors that achieve short- ...
.
The
X-ray crystal structures of trypanothione reductase enzymes from several
trypanosomatids species have been solved, including those from
Crithidia fasciculata
''Crithidia fasciculata'' is a species of parasitic excavates. ''C. fasciculata'', like other species of '' Crithidia'' have a single host life cycle with insect host, in the case of ''C. fasciculata'' this is the mosquito. ''C. fasciculata'' h ...
,
Leishmania infantum
''Leishmania infantum'' is the causative agent of infantile visceral leishmaniasis in the Mediterranean region and in Latin America, where it has been called ''Leishmania chagasi''. It is also an unusual cause of cutaneous leishmaniasis, which i ...
,
Trypanosoma brucei
''Trypanosoma brucei'' is a species of parasitic kinetoplastid belonging to the genus '' Trypanosoma'' that is present in sub-Saharan Africa. Unlike other protozoan parasites that normally infect blood and tissue cells, it is exclusively extrace ...
and
Trypanosoma cruzi
''Trypanosoma cruzi'' is a species of parasitic euglenoids. Among the protozoa, the trypanosomes characteristically bore tissue in another organism and feed on blood (primarily) and also lymph. This behaviour causes disease or the likelihood o ...
. The structures reveal that trypanothione reductase forms
homodimers in solution with each of the two individual subunits comprising an FAD-binding domain, an NADPH-binding domain and an interface domain. Examples of trypanothione reductase inhibitors include 5-Nitro-Imidazole, Febrifugine, Imipramine and Benzoxaborole.
References
*
*
*
*
EC 1.8.1
NADPH-dependent enzymes
Flavin enzymes
Enzymes of unknown structure
{{1.8-enzyme-stub