What is the difference between reversible and irreversible enzyme inhibitors?

Reversible enzyme inhibitors can be removed, while irreversible ones cannot.

Enzyme inhibitors are molecules that bind to enzymes and reduce their activity. Reversible inhibitors can bind and unbind from the enzyme, meaning that their effect is temporary. They can be competitive, non-competitive, or uncompetitive. Competitive inhibitors bind to the active site of the enzyme, preventing the substrate from binding. Non-competitive inhibitors bind to a different site on the enzyme, changing its shape and reducing its activity. Uncompetitive inhibitors bind to the enzyme-substrate complex, preventing the reaction from proceeding.

Irreversible inhibitors, on the other hand, bind permanently to the enzyme, meaning that their effect is permanent. They can be classified as group-specific, which react with specific amino acid residues, or suicide inhibitors, which bind to the enzyme and undergo a chemical reaction that inactivates it. Examples of irreversible inhibitors include aspirin, which irreversibly inhibits the enzyme cyclooxygenase, and nerve gases, which irreversibly inhibit the enzyme acetylcholinesterase.

The difference between reversible and irreversible inhibitors is important in drug design. Reversible inhibitors are often used as drugs because they can be removed if necessary, and their effects are temporary. Irreversible inhibitors, on the other hand, are often used as pesticides or in chemotherapy because their permanent effects can be used to kill cells or organisms. However, irreversible inhibitors can also have unintended side effects, so their use must be carefully controlled.