isomeraser

Isomeraser is not a standard term in biochemistry or enzymology. When encountered, it is usually either a playful or fictional designation or a typographical variation of the established term isomerase. In scientific usage, the correct term is isomerase, an enzyme that catalyzes the rearrangement of atoms within a molecule to form isomers without a change in oxidation state.

Isomerases encompass several subtypes, including racemases and epimerases, mutases, and various intramolecular transferases. They drive the interconversion of stereoisomers, structural isomers, or rearranged functional groups, enabling key metabolic processes. Examples include enzymes that convert glucose-6-phosphate to fructose-6-phosphate, glyceraldehyde-3-phosphate to dihydroxyacetone phosphate, and ribose-5-phosphate to ribulose-5-phosphate. These reactions are essential in glycolysis, the pentose phosphate pathway, and other central metabolic routes.

Mechanistically, isomerases often use acid-base catalysis, metal ion coordination, or covalent catalysis to stabilize transition states and reposition atoms within the molecule. Their activity changes the structure of substrates without altering their overall oxidation state, allowing cells to access different metabolic fates.

Classification and nomenclature: In the Enzyme Commission (EC) system, isomerases are EC class 5, with subcategories such as 5.1 (racemases and epimerases), 5.2 (intramolecular oxidoreductases), 5.3 (intramolecular transferases, i.e., mutases), 5.4 (intramolecular transferases), and others depending on the type of isomerization.

If you encounter the term isomeraser, verify whether it refers to the standard isomerase or appears in a fictional or nonstandard context. See also Isomerase, Enzyme, Metabolism.