List of EC numbers (EC 5)

List of EC numbers (EC 5) encompasses a group of enzymes classified under EC 5 according to the Enzyme Commission (EC) numbering system. This category specifically includes enzymes known as isomerases, which catalyze the rearrangement of atoms within a molecule. Isomerases play crucial roles in various biological processes, including but not limited to, metabolism, DNA repair, and the synthesis of important biomolecules.

Overview

Isomerases (EC 5) facilitate the conversion of molecules from one isomeric form to another. This includes structural isomers, where the connectivity of atoms differs, as well as stereoisomers, where the spatial arrangement of atoms varies. The EC 5 category is further subdivided into several subclasses based on the type of isomerization reaction they catalyze. These subclasses include racemases and epimerases (EC 5.1), cis-trans isomerases (EC 5.2), intramolecular oxidoreductases (EC 5.3), intramolecular transferases (EC 5.4), and intramolecular lyases (EC 5.5).

Subclasses and Examples

Racemases and Epimerases (EC 5.1)

These enzymes catalyze the conversion between enantiomers or diastereomers. An example is Alanine racemase (EC 5.1.1.1), which is involved in the synthesis of D-alanine, a component of bacterial cell walls.

Cis-trans Isomerases (EC 5.2)

Cis-trans isomerases, such as Peptidylprolyl isomerase (EC 5.2.1.8), facilitate the interconversion between cis and trans isomers of peptide bonds, which is critical for protein folding.

Intramolecular Oxidoreductases (EC 5.3)

These enzymes catalyze the transfer of hydrogen or oxygen atoms within a molecule. An example is Glucose-6-phosphate isomerase (EC 5.3.1.9), which plays a key role in both glycolysis and gluconeogenesis.

Intramolecular Transferases (EC 5.4)

Intramolecular transferases, such as Phosphoglucomutase (EC 5.4.2.2), are involved in the rearrangement of phosphate groups within a molecule, crucial for carbohydrate metabolism.

Intramolecular Lyases (EC 5.5)

These enzymes catalyze the breaking of chemical bonds by means other than hydrolysis and oxidation, often forming a new double bond or a new ring structure. An example is Isopentenyl-diphosphate delta-isomerase (EC 5.5.1.4), which is involved in terpenoid biosynthesis.

Importance in Medicine and Biotechnology

Isomerases are of significant interest in both medicine and biotechnology. They are involved in the synthesis of many biologically active molecules, making them targets for drug discovery and development. For instance, inhibitors of Peptidylprolyl isomerase are being explored for their potential in treating diseases such as cancer and Alzheimer's disease.

In biotechnology, isomerases are used in the synthesis of chiral compounds, which are important in the pharmaceutical industry. The ability to selectively produce one enantiomer over another can lead to drugs with higher efficacy and fewer side effects.

See Also

• Enzyme
• Metabolism
• Protein folding
• Chirality