In enzymology, phenylpyruvate tautomerase or Macrophage migration inhibitory factor (EC 5.3.2.1) is an enzyme that catalyzes the chemical reaction Phenylpyruvate tautomerase has also been found to exhibit the same keto-enol tautomerism for 4-Hydroxyphenylpyruvic acid, which is structurally similar to phenylpyruvate but contains an additional hydroxyl moiety in the para position of the aromatic ring.
[1] This enzyme belongs to the family of isomerases, specifically those intramolecular oxidoreductases interconverting keto- and enol-groups.
The systematic name of this enzyme class is phenylpyruvate keto---enol-isomerase.
This enzyme is also called phenylpyruvic keto-enol isomerase.
As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes 1GYJ, 1GYX, 1GYY, 2GDG, 2OOH, 2OOW, and 2OOZ.