20 by: Ayden Matt

Student – Ayden Matt

Enzyme & EC # – Carbonic Anhydrase; E.C. # 4.2.1.1.

Where is the enzyme found? There are three classes of carbonic anhydrases, alpha class for humans and animals, beta class for plants and bacteria, and gamma class for archaea/ancient prokaryotes. This project is based on the alpha class, and this enzyme is found in the red blood cells alongside hemoglobin.

What does the enzyme do? Carbonic Anhydrase essentially joins water and carbon dioxide to form bicarbonate and H+. An OH bound to the zinc of Carbonic Anhydrase attacks the carbon dioxide Water then displaces the bicarbonate by attacking the zinc. Several other sites on the enzyme assist in making conditions favorable for this reaction to occur. Lone pairs on a nitrogen in the enzyme pull a hydrogen off water, and a series of proton movements through the enzyme generates H+. This is used in the body to generate carbonic acid which is a very important buffer in blood.

Other interesting facts about Carbonic Anhydrase – This enzyme is extra interesting because it has a large number of isozymes! For alpha class, which I looked at for this project, at least 14 isozymes have been identified, and some are some of the most efficient catalysts known!

References

Holliday, G.L., Sarkies, P. Carbonate dehydratase. Mechanism and Catalytic Site Atlas. https://www.ebi.ac.uk/thornton-srv/m-csa/entry/216/. (accessed Oct 9, 2024).
Morris, R.H., Lee, A., and Hadzovic, A. (2011). A Tour of Carbonic Anhydrase. Retrieved
from https://sites.chem.utoronto.ca/chemistry/coursenotes/GTM/JM/carb_anhyd/start.htm. (accessed Oct 7, 2024).