Classification of enzymes

Classification of enzymes
    • In olden days enzymes have been named by adding the suffix -ase to the name of the substrate (the molecule on which the enzyme acts).
    • Ex. Urease (Substrate urea) Arginase (Substrate arginine).
    • Recent studies on the mechanism of enzyme catalysed reactions have led to a more rational classification of enzymes.
    • The International Union of Biochemistry (IUB) established a commission on enzyme nomenclature to adopt a systematic classification and nomenclature of all the existing and yet to be discovered enzymes.
    • This system is based on the substrate and reaction specificity.
    • Although, this International Union of Biochemistry system is complex, it is precise, descriptive and informative.
    • IUB system classifies enzymes into six major classes (should be written in specific order only)
    1. Oxidoreductases
    2. Transferases
    3. Hydrolases
    4. Lyases
    5. Isomerases
    6. Ligases
    • Again each class is divided into subclasses according to the type of reaction catalysed.
    • Each enzyme is assigned a recommended name usually a short for everyday use, a systematic name which identify the reaction it catalyses and a classification number which is used where accurate and unambiguous identification of an enzyme is required

Last modified: Wednesday, 28 March 2012, 4:14 PM