In
enzymology
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 ...
, a testosterone 17beta-dehydrogenase is an
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 ...
that
catalyzes
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...
the
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, ...
between
testosterone
Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...
and
androst-4-ene-3,17-dione. 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 ut ...
s, specifically those acting on the CH-OH group of donor with NAD
+ or NADP
+ as acceptor.
Names
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 semitrivi ...
of this enzyme class is 17beta-hydroxysteroid:NAD
+ 17-oxidoreductase. Other names in common use include 17-ketoreductase and 17beta-HSD. This enzyme participates in androgen and
estrogen
Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...
metabolism.
Variants
There are two variants of the enzyme, one that uses
NAD+ as a substrate, and one that uses
NADP+ as acceptor.
NAD+
This variant of testosterone 17beta-dehydrogenase () catalyzes the reaction
:testosterone + NAD
+ androst-4-ene-3,17-dione + NADH + H
+
Thus, the two
substrates of this enzyme are
testosterone
Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...
and
NAD+, whereas its 3
products
Product may refer to:
Business
* Product (business), an item that can be offered to a market to satisfy the desire or need of a customer.
* Product (project management), a deliverable or set of deliverables that contribute to a business solution
...
are
androst-4-ene-3,17-dione,
NADH
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an ade ...
, and
H+.
NADP+
This variant of testosterone 17beta-dehydrogenase () catalyzes the reaction
:testosterone + NADP
+ androst-4-ene-3,17-dione + NADPH + H
+
Thus, the two
substrates of this enzyme are testosterone and
NADP+, whereas its 3
products
Product may refer to:
Business
* Product (business), an item that can be offered to a market to satisfy the desire or need of a customer.
* Product (project management), a deliverable or set of deliverables that contribute to a business solution
...
are
androst-4-ene-3,17-dione,
NADPH
Nicotinamide adenine dinucleotide phosphate, abbreviated NADP or, in older notation, TPN (triphosphopyridine nucleotide), is a cofactor used in anabolic reactions, such as the Calvin cycle and lipid and nucleic acid syntheses, which require N ...
, and
H+.
See also
*
Testosterone glucuronide
Testosterone glucuronide is an endogenous, naturally occurring steroid and minor urinary metabolite of testosterone
Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the deve ...
References
*
*
*
External links
Testosterone Enhancement
EC 1.1.1
Testosterone
NADH-dependent enzymes
NADPH-dependent enzymes
Enzymes of unknown structure
Enzymes of known structure
{{1.1.1-enzyme-stub