Oxidoreductase
In
transmembrane helix.[3]
Reactions
For example, an enzyme that catalyzed this reaction would be an oxidoreductase:
- A– + B → A + B–
In this example, A is the reductant (electron donor) and B is the oxidant (electron acceptor).
In biochemical reactions, the redox reactions are sometimes more difficult to see, such as this reaction from glycolysis:
- Pi + glyceraldehyde-3-phosphate + NAD+ → NADH + H+ + 1,3-bisphosphoglycerate
In this reaction, NAD+ is the oxidant (electron acceptor), and
glyceraldehyde-3-phosphate
is the reductant (electron donor).
Nomenclature
Proper names of oxidoreductases are formed as "donor:acceptor oxidoreductase"; however, other names are much more common.[citation needed]
- The common name is "donor dehydrogenase" when possible, such as glyceraldehyde-3-phosphate dehydrogenase for the second reaction above.
- Common names are also sometimes formed as "acceptor reductase", such as NAD+ reductase.
- "Donor O2is the acceptor.
Classification
Oxidoreductases are classified as EC 1 in the EC number classification of enzymes. Oxidoreductases can be further classified into 21 subclasses:
- alcohol oxidoreductases such as methanol dehydrogenase)
- EC 1.2 includes oxidoreductases that act on the aldehyde or oxo group of donors
- CH-CH oxidoreductases)
- EC 1.4 includes oxidoreductases that act on the CH-NH2 group of donors (Amino acid oxidoreductases, Monoamine oxidase)
- EC 1.5 includes oxidoreductases that act on CH-NH group of donors
- EC 1.6 includes oxidoreductases that act on NADH or NADPH
- EC 1.7 includes oxidoreductases that act on other nitrogenous compounds as donors
- EC 1.8 includes oxidoreductases that act on a sulfur group of donors
- EC 1.9 includes oxidoreductases that act on a heme group of donors
- diphenolsand related substances as donors
- EC 1.11 includes oxidoreductases that act on peroxide as an acceptor (peroxidases)
- EC 1.12 includes oxidoreductases that act on hydrogen as donors
- EC 1.13 includes oxidoreductases that act on single donors with incorporation of molecular oxygen (oxygenases)
- EC 1.14 includes oxidoreductases that act on paired donors with incorporation of molecular oxygen
- EC 1.15 includes oxidoreductases that act on superoxide radicals as acceptors
- EC 1.16 includes oxidoreductases that oxidize metal ions
- EC 1.17 includes oxidoreductases that act on CH or CH2 groups
- EC 1.18 includes oxidoreductases that act on iron-sulfur proteins as donors
- EC 1.19 includes oxidoreductases that act on reduced flavodoxin as a donor
- EC 1.20 includes oxidoreductases that act on phosphorus or arsenic in donors
- EC 1.21 includes oxidoreductases that act on X-H and Y-H to form an X-Y bond
See also
- Hydroxylase
- List of enzymes
References
External links
- Media related to Oxidoreductases at Wikimedia Commons
- EC 1 Introduction from the Department of Chemistry at Queen Mary, University of London