Hydrataasi

Hydrataasi is a class of enzymes that catalyze the addition of water to a carbon–carbon double bond (hydration) or, in the reverse reaction, the removal of water (dehydration). In enzyme nomenclature, hydrataasit are grouped within the lyases, specifically the subcategory EC 4.2.1, which covers carbon–oxygen lyases that form or cleave water across double bonds. The chemical outcome typically involves converting an alkene to an alcohol or carbonyl compound, or performing the reverse transformation.

Biological role and examples span central metabolism. In fatty acid β-oxidation, enoyl-CoA hydratas can add water to trans-2-enoyl-CoA to yield L-3-hydroxyacyl-CoA. In the citric acid cycle, fumarate hydrataasi catalyzes the conversion of fumarate to malate. Other hydrataasit participate in various biosynthetic pathways, including isoprenoid and amino acid metabolism, as well as the formation of hydroxy compounds in secondary metabolism.

Structure and mechanism vary among hydrataasit. Many form homodimers or higher-order oligomers and may require cofactors such as divalent metal ions or metal clusters. Mechanistic strategies often rely on catalytic base–acid pairs to activate water and guide its addition to the substrate, with active sites tailored to specific substrates and reaction directions.

Clinical and biotechnological relevance is active in research and applications. Defects in certain hydrataasit, such as fumarate hydrataasi, can be associated with metabolic disorders and cancer-related metabolic changes. Hydrataasi are also explored in biocatalysis and synthetic biology for stereoselective hydration of alkenes under mild conditions, offering potential routes for green chemical synthesis.