Dehydratase Explained

Dehydratases are a group of lyase enzymes that form double and triple bonds in a substrate through the removal of water.^[1] They can be found in many places including the mitochondria, peroxisome and cytosol.^[2] There are more than 150 different dehydratase enzymes^[3] that are classified into four groups. Dehydratases can act on hydroxyacyl-CoA with or without cofactors, and some have a metal and non-metal cluster act as their active site.

Pathology

A dehydratase deficiency in the body can lead to a less severe condition of hyperphenylalaninemia, which involves an over presence of phenylalanine in the blood. It is caused by a genetic recessive disorder in the autosomal DNA.^[4]

Examples

Common dehydratases include:

• Delta-aminolevulinic acid dehydratase (ADA-D) is found in blood and is involved in the production of the heme group of globins.^[5] People exposed to lead will have a decrease in ADA-D activity.^[6]
• Serine dehydratase is mostly found in the liver and catalyzes the reaction of turning serine into pyruvate and ammonia. In a diet of increased protein, the activity of serine dehydratase is increased.^[7]
• Arogenate dehydratase is found mostly in the chloroplasts of higher plants. It catalyzes the reaction of turning L-arogenate into L-phenylalanine.^[8]

Notes and References

1. Dehydratase. The Free Dictionary.
2. Cook L, Nagi MN, Suneja SK, Hand AR, Cinti DL . Evidence that beta-hydroxyacyl-CoA dehydrase purified from rat liver microsomes is of peroxisomal origin . The Biochemical Journal . 287 (Pt 1) . Pt 1 . 91–100 . October 1992 . 1417796 . 10.1042/bj2870091 . 1133128 .
3. Web site: ENZYME: 4.2.1.-. enzyme.expasy.org. 2016-11-05.
4. Web site: Dehydratase deficiency . Orphanet . 2016-11-01 .
5. Web site: ALAD gene . Genetics Home Reference . U.S. National Library of Medicine . 2016-11-04 .
6. Burch HB, Siegel AL . Improved Method for Measurement of delta-Aminolevulinic Acid DehydrataseActivity of Human Erythrocytes . Clinical Chemistry . 17 . 10 . 1038–41 . October 1971 . 4328740 . 10.1093/clinchem/17.10.1038 .
7. Mauron J, Mottu F, Spohr G . Reciprocal Induction and Repression of Serine Dehydratase and Phosphoglycerate Dehydrogenase by Proteins and Dietary-Essential Amino Acids in Rat Liver . European Journal of Biochemistry . 32 . 2 . 331–42 . January 1973 . 4347092 . 10.1111/j.1432-1033.1973.tb02614.x .
8. Jung E, Zamir LO, Jensen RA . Chloroplasts of higher plants synthesize L-phenylalanine via L-arogenate . Proceedings of the National Academy of Sciences of the United States of America . 83 . 19 . 7231–5 . October 1986 . 3463961 . 10.1073/pnas.83.19.7231 . free . 1986PNAS...83.7231J . 386689 .