Phenylpyruvate tautomerase

Phenylpyruvate tautomerase (PPT), also known as Macrophage migration inhibitory factor (MIF), is an enzyme that in humans is encoded by the MIF gene. This enzyme is involved in the metabolism of amino acids and fatty acids, and plays a crucial role in the immune system.

Function

Phenylpyruvate tautomerase catalyzes the conversion of phenylpyruvate to phenylacetate, a reaction that is part of the phenylalanine degradation pathway. This enzyme is also known to have a secondary function as a cytokine, known as Macrophage migration inhibitory factor. As a cytokine, it plays a role in the regulation of macrophage function in host defense and may be involved in the pathogenesis of inflammatory diseases.

Structure

The MIF gene, which encodes phenylpyruvate tautomerase, is located on chromosome 22 in humans. The enzyme itself is a trimer, with each subunit consisting of 114 amino acids. The active site of the enzyme is located in a deep pocket in the center of the trimer.

Clinical significance

Alterations in the function of phenylpyruvate tautomerase have been associated with a variety of diseases, including rheumatoid arthritis, asthma, and cancer. In particular, overexpression of this enzyme has been observed in several types of cancer, suggesting a potential role in tumorigenesis.

See also

• Macrophage migration inhibitory factor
• Enzyme
• Metabolism
• Amino acid
• Fatty acid
• Immune system
• Phenylalanine
• Macrophage
• Chromosome 22
• Rheumatoid arthritis
• Asthma
• Cancer