deshidratasa

Deshidratasa is the term used for enzymes that catalyze dehydration reactions, removing a molecule of water from a substrate to form a double bond or an unsaturated product. In enzymology they are generally classified as lyases, specifically dehydration lyases, though some dehydration steps are described within other enzyme categories depending on the pathway.

Typical reactions carried out by deshidratasas include the elimination of water from organic substrates. A well-known example in central metabolism is the dehydration of 2-phosphoglycerate to phosphoenolpyruvate in glycolysis, catalyzed by enolase. Another important example is aconitase, which catalyzes the dehydration of citrate to cis-aconitate as part of the citric acid cycle, followed by hydration to isocitrate. Other deshidratasas participate in amino-acid metabolism and biosynthetic pathways, removing water to generate reactive intermediates or to enable subsequent transformations.

Mechanism and cofactors vary among deshidratasas. Some rely on metal ions, such as magnesium, to stabilize intermediates during elimination, while others use iron-sulfur clusters or specific amino-acid residues to facilitate water removal and the ensuing chemical steps.

Biological significance is broad: dehydration steps are common in both central metabolism and specialized pathways, enabling substrate rearrangements, the formation of double bonds, or preparation of substrates for subsequent enzymatic reactions. Defects or regulation of deshidratasas can influence metabolic flux and energy production in cells.

Terminology: in Spanish-language sources, deshidratasa denotes enzymes that catalyze water removal; in English-language databases, these enzymes are typically referred to as dehydratases and are categorized within the lyase family (EC class 4).