The
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...
sulfinoalanine decarboxylase ()
catalyzes
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
the
chemical reaction
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and break ...
:3-sulfino-L-alanine
hypotaurine + CO
2
Hence, this enzyme has one
substrate
Substrate may refer to:
Physical layers
*Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached
** Substrate (locomotion), the surface over which an organism lo ...
, 3-sulfino-L-alanine (also known as
Cysteine sulfinic acid), and two
products,
hypotaurine and
CO2.
This enzyme belongs to the family of
lyase
In biochemistry, a lyase is an enzyme that catalyzes the breaking (an elimination reaction) of various chemical bond
A chemical bond is a lasting attraction between atoms or ions that enables the formation of molecules and crystals. The bon ...
s, specifically the carboxy-lyases, which cleave carbon-carbon bonds. The
systematic name of this enzyme class is 3-sulfino-L-alanine carboxy-lyase (hypotaurine-forming). Other names in common use include cysteine-sulfinate decarboxylase, L-cysteinesulfinic acid decarboxylase, cysteine-sulfinate decarboxylase, CADCase/CSADCase, CSAD, cysteic decarboxylase, cysteinesulfinic acid decarboxylase, cysteinesulfinate decarboxylase, sulfoalanine decarboxylase, and 3-sulfino-L-alanine carboxy-lyase. This enzyme participates in
taurine
Taurine (), or 2-aminoethanesulfonic acid, is an organic compound that is widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine, and accounts for up to 0.1% of total human body weight. It ...
metabolism. It employs one
cofactor,
pyridoxal phosphate
Pyridoxal phosphate (PLP, pyridoxal 5'- phosphate, P5P), the active form of vitamin B6, is a coenzyme in a variety of enzymatic reactions. The International Union of Biochemistry and Molecular Biology has catalogued more than 140 PLP-depende ...
.
Structural studies
As of late 2007, only one
structure has been solved for this class of enzymes, with the
PDB accession code .
References
*
*
EC 4.1.1
Pyridoxal phosphate enzymes
Enzymes of known structure
{{4.1-enzyme-stub