Glyceollin synthase
Encyclopedia
In enzymology, a glyceollin synthase is an enzyme
that catalyzes
the last committed step
in glyceollin
biosynthesis
. This enzyme has been classified as a cytochrome
dependent monooxygenase
. It uses cyclization of prenyl
residue to convert glyceollidins (I and II) into glyceollins (I - III).
This enzyme catalyzes the following chemical reaction
:
The five substrates
of this enzyme are 2-dimethylallyl-(6aS,11aS)-3,6a,9-trihydroxypterocarpan, 4-dimethylallyl-(6aS,11aS)-3,6a,9-trihydroxypterocarpan, NADPH
, H+
, and O2
, whereas its three products
are glyceollin
, NADP+
, and H2O
.
This enzyme belongs to the family of oxidoreductase
s, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with NADH or NADPH as one donor, and incorporation of one atom o oxygen into the other donor. The systematic name of this enzyme class is 2-(or 4-)dimethylallyl-(6aS,11aS)-3,6a,9-trihydroxypterocarpan,NADPH:oxyge n oxidoreductase (cyclizing). This enzyme participates in isoflavonoid biosynthesis.
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
that catalyzes
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
the last committed step
Committed step
In enzymology, the committed step is an effectively irreversible enzymatic reaction that occurs at a branch point during the biosynthesis of some molecules.-What it means:...
in glyceollin
Glyceollin
Glyceollins are a family of prenylated pterocarpan found in ineffective types of nodule in soybean in response to symbiotic infection. They are phytoalexins with an antiestrogenic activity.Molecules found in the family are :* Glyceollin I* Glyceollin II...
biosynthesis
Biosynthesis
Biosynthesis is an enzyme-catalyzed process in cells of living organisms by which substrates are converted to more complex products. The biosynthesis process often consists of several enzymatic steps in which the product of one step is used as substrate in the following step...
. This enzyme has been classified as a cytochrome
Cytochrome
Cytochromes are, in general, membrane-bound hemoproteins that contain heme groups and carry out electron transport.They are found either as monomeric proteins or as subunits of bigger enzymatic complexes that catalyze redox reactions....
dependent monooxygenase
Monooxygenase
Monooxygenases are enzymes that incorporate one hydroxyl group into substrates in many metabolic pathways. In this reaction, two atoms of dioxygen are reduced to one hydroxyl group and one H2O molecule by the concomitant oxidation of NADH.-Classification:...
. It uses cyclization of prenyl
Prenylation
Prenylation, or isoprenylation, or lipidation is the addition of hydrophobic molecules to a protein. It is usually assumed that prenyl groups facilitate attachment to cell membranes, similar to lipid anchor like the GPI anchor, though direct evidence is missing...
residue to convert glyceollidins (I and II) into glyceollins (I - III).
This enzyme catalyzes the following chemical reaction
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
:
- 2-(or 4-)dimethylallyl-(6aS,11aS)-3,6a,9-trihydroxypterocarpan + NADPH + H+ + O2 glyceollin + NADP+ + 2 H2O
The five substrates
Substrate (biochemistry)
In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate. In the case of a single substrate, the substrate binds with the enzyme active site, and an enzyme-substrate complex is formed. The substrate is transformed into one or...
of this enzyme are 2-dimethylallyl-(6aS,11aS)-3,6a,9-trihydroxypterocarpan, 4-dimethylallyl-(6aS,11aS)-3,6a,9-trihydroxypterocarpan, NADPH
Nicotinamide adenine dinucleotide phosphate
Nicotinamide adenine dinucleotide phosphate, abbreviated NADP or TPN in older notation , is a coenzyme used in anabolic reactions, such as lipid and nucleic acid synthesis, which require NADPH as a reducing agent....
, H+
Hydrogen ion
Hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes.Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions....
, and O2
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
, whereas its three products
Product (chemistry)
Product are formed during chemical reactions as reagents are consumed. Products have lower energy than the reagents and are produced during the reaction according to the second law of thermodynamics. The released energy comes from changes in chemical bonds between atoms in reagent molecules and...
are glyceollin
Glyceollin
Glyceollins are a family of prenylated pterocarpan found in ineffective types of nodule in soybean in response to symbiotic infection. They are phytoalexins with an antiestrogenic activity.Molecules found in the family are :* Glyceollin I* Glyceollin II...
, NADP+
Nicotinamide adenine dinucleotide phosphate
Nicotinamide adenine dinucleotide phosphate, abbreviated NADP or TPN in older notation , is a coenzyme used in anabolic reactions, such as lipid and nucleic acid synthesis, which require NADPH as a reducing agent....
, and H2O
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
.
This enzyme belongs to the family of oxidoreductase
Oxidoreductase
In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule to another...
s, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with NADH or NADPH as one donor, and incorporation of one atom o oxygen into the other donor. The systematic name of this enzyme class is 2-(or 4-)dimethylallyl-(6aS,11aS)-3,6a,9-trihydroxypterocarpan,NADPH:oxyge n oxidoreductase (cyclizing). This enzyme participates in isoflavonoid biosynthesis.