In
enzymology, a glutamate synthase (NADPH) () 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 ...
:L-glutamine +
2-oxoglutarate + NADPH + H
+ 2 L-glutamate + NADP
+
Thus, the four
substrates of this enzyme are
L-glutamine
Glutamine (symbol Gln or Q) is an α-amino acid that is used in the biosynthesis of proteins. Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide. It is classified as a charge-neutral, ...
,
2-oxoglutarate (α-ketoglutarate),
NADPH, and
H+, whereas the two
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
L-glutamate
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...
and
NADP+.
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 the CH-NH2 group of donors with NAD+ or NADP+ as acceptor. This enzyme participates in
glutamate metabolism and
nitrogen metabolism. It has 5
cofactors:
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- ...
,
Iron
Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...
,
FMN,
Sulfur, and
Iron-sulfur.
It occurs in bacteria and plants but not animals, and is important as it provides glutamate for the
glutamine synthetase
Glutamine synthetase (GS) () is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine:
Glutamate + ATP + NH3 → Glutamine + ADP + phosphate
Glutam ...
reaction.
Nomenclature
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 L-glutamate:NADP+ oxidoreductase (transaminating). Other names in common use include:
* glutamate (reduced nicotinamide adenine dinucleotide phosphate), synthase,
* glutamate synthase (NADPH),
* glutamate synthetase (NADP),
* glutamine amide-2-oxoglutarate aminotransferase (oxidoreductase, NADP),
* glutamine-ketoglutaric aminotransferase,
* L-glutamate synthase,
* L-glutamate synthetase,
* L-glutamine:2-oxoglutarate aminotransferase, NADPH oxidizing,
* NADPH-dependent glutamate synthase,
* NADPH-glutamate synthase, and
* NADPH-linked glutamate synthase.
Structural studies
As of late 2007, only one
structure has been solved for this class of enzymes, with the
PDB accession code .
See also
*
Glutamate synthase (NADH)
*
Glutamate synthase (ferredoxin)
References
Further reading
*
*
EC 1.4.1
NADPH-dependent enzymes
Flavoproteins
Iron enzymes
Sulfur enzymes
Iron-sulfur enzymes
Enzymes of known structure
{{1.4-enzyme-stub