Enzyme Inhibitors

Modern drug development is about specificity.

Enzyme inhibitors offer a powerful method for blocking specific activity at the metabolic level

• Enzymes facilitate many of the chemical reactions that are necessary for life: from digestion of nutrients to synthesis of DNA.
• Enzymes display a very high specificity-of-action, with any given enzyme generally recognizing only one or a handful of potential substrates.
• Inhibition of a specific enzyme allows a researcher to better understand a metabolic pathway, and opens up avenues for novel drug design

Enzyme inhibitors act by blocking or slowing enzymatic function, significantly reducing the capacity to convert substrates into products

Enzyme inhibitors may work in one of several different ways

• Some inhibitors prevent enzymes from recognizing or binding to substrates, either by masking the substrate or by blocking the active-site on the enzyme. (Competitive inhibition).
• Alternatively, some enzyme inhibitors may significantly reduce enzymatic activity without affecting substrate recognition or binding. (Non-competitive inhibition)
• Some enzyme inhibitors are capable of affecting enzymes in a variety of different ways, and can provide a mixture of competitive and non-competitive inhibition (Mixed-inhibition)

Enzyme inhibitors may be reversible or irreversible

• Reversible enzyme inhibitors form a non-covalent bond with an enzyme. They may temporarily block or slow enzymatic function, but the effects are (by nature) reversible. Reversible enzyme inhibitors are typically easily removed by dilution or dialysis.
• Irreversible enzyme inhibitors form a covalent bond with an enzyme. They permanently alter the chemical structure of the enzyme thereby irreversibly slowing or blocking enzymatic function.