AAT Bioquest

What are the different types of reversible enzyme inhibitors?

Posted July 22, 2020


There are 4 types of reversible enzyme inhibitors.

  • Competitive: A competitive inhibitor and the substrate cannot bind to the enzyme at the same time. This kind of inhibitors often has very similar structure with the real substrate of the enzyme. The inhibition can be overcome with substrate concentration.
  • Uncompetitive: An uncompetitive inhibitor binds only to the substrate-enzyme complex, which inactivates the enzyme-substrate complex. This type of inhibitor is most effective when the substrate concentration is high.
  • Non-competitive: A non-competitive inhibitor binds to a site other than where the substrate binds; therefore, it can bind to both the enzyme and enzyme-substrate complex. The binding of substrate is not affected, but the catalytic efficiency of the enzyme is reduced by the inhibitor. Since the binding of substrate remains unchanged, this inhibition cannot be overcome with high substrate concentration.
  • Mixed: A mixed inhibitor also can bind to both the enzyme and the enzyme-substrate complex. However, the binding of inhibitor can affect the binding of substrate by changing the conformation of the enzyme. This type of inhibition can be reduced but not eliminated by increasing concentration of substrates.
Additional resources

Amplite™ Fluorimetric Glucose-6-Phosphate Dehydrogenase (G6PD) Assay Kit

Amplite™ Fluorimetric Coenzyme A Quantitation Kit *Green Fluorescence*

Lodish, H., Berk, A., Kaiser, C. A., Krieger, M., Scott, M. P., Bretscher, A., ... & Matsudaira, P. (2008). Molecular cell biology. Macmillan.

Berg, J. M., Tymoczko, J. L., & Stryer, L. (2008). Biochemistry (Loose-Leaf). Macmillan.