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 ...
, phenylpyruvate tautomerase or
Macrophage migration inhibitory factor
Macrophage migration inhibitory factor (MIF), also known as glycosylation-inhibiting factor (GIF), L-dopachrome isomerase, or phenylpyruvate tautomerase is a protein that in humans is encoded by the ''MIF'' gene. MIF is an important regulator of ...
() 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, ...
keto-
phenylpyruvate
Phenylpyruvic acid is the organic compound with the formula C6H5CH2C(O)CO2H. It is a keto acid.
Occurrence and properties
The compound exists in equilibrium with its (''E'')- and (''Z'')-enol tautomers. It is a product from the oxidative deam ...
enol-phenylpyruvate
Phenylpyruvate tautomerase has also been found to exhibit the same keto-enol tautomerism for
4-Hydroxyphenylpyruvic acid
4-Hydroxyphenylpyruvic acid (4-HPPA) is an intermediate in the metabolism of the amino acid phenylalanine. The aromatic side chain of phenylalanine is hydroxylated by the enzyme phenylalanine hydroxylase to form tyrosine. The conversion from tyr ...
, which is structurally similar to phenylpyruvate but contains an additional hydroxyl moiety in the para position of the aromatic ring.
This enzyme belongs to the family of
isomerase
In biochemistry, isomerases are a general class of enzymes that convert a molecule from one isomer to another. Isomerases facilitate intramolecular rearrangements in which chemical bond, bonds are Bond cleavage, broken and formed. The general form ...
s, specifically those intramolecular
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 interconverting keto- and enol-groups. 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 phenylpyruvate keto---enol-isomerase. This enzyme is also called phenylpyruvic keto-enol isomerase. This enzyme participates in
tyrosine metabolism
-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a conditionally essential amino acid with a polar side group. The word "tyrosine" is f ...
and
phenylalanine metabolism
Phenylalanine (symbol Phe or F) is an essential α-amino acid with the formula . It can be viewed as a benzyl group substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of alanine. This essential amino a ...
.
Structural studies
As of late 2007, 7
structures
A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...
have been solved for this class of enzymes, with
PDB accession codes , , , , , , and .
References
*
*
*
EC 5.3.2
Enzymes of known structure
{{isomerase-stub