Copper enyzmes often have functions which can be performed by corresponding iron compounds. This is due to similar redox potentials.
Copper enzymes can be found in:
- Haemocyanin (O2 transport)
- Tyrosinase (oxygenation reactions)
- Nitrite reductase
- Superoxide dismutase (Antioxidant)
- "Blue" copper proteins
Histidine, methionine and cysteine residues are often used to coordinate the copper atoms. Depending on the function of the enzyme, oxygen donor atoms can also be bound.
Copper centers are often coupled to other metal centers.