Metalloenzymes are enzymes that contain one or more metal ions as part of their structure, which are essential for their biological activity. These metal ions can help the enzyme:
- Stabilize structure – The metal can help maintain the proper 3D shape of the enzyme.
- Participate in catalysis – Metals can help speed up chemical reactions by acting as electron donors or acceptors.
- Bind substrates – Metals can help the enzyme hold onto the molecules it acts on.
Examples of metalloenzymes and their metals:
- Carbonic anhydrase – contains zinc (Zn²⁺); helps convert carbon dioxide and water into bicarbonate.
- Cytochrome c oxidase – contains iron (Fe) and copper (Cu); important in cellular respiration.
- Superoxide dismutase (SOD) – contains copper (Cu) and zinc (Zn) or manganese (Mn); protects cells from harmful free radicals.
In simple terms, metalloenzymes are enzymes that need metal ions to work properly, and without these metals, the enzyme often cannot perform its function.