An allosteric enzyme is an chemical involved in the regulation of cell processes. These enzymes play a role in cell metabolism by catalyzing various events, like other enzymes, and they can also be used to control the rate of metabolism. They are used by the cell to keep operating efficiency high and to prevent the waste of energy and the unnecessary production inside the cell. Researchers who study them often work with bacteria such as Escherichia coli to learn more about how these enzymes function and what happens when their structure changes.
Function of enzymes can be changed by binding of inhibitors or activators to the active site on the enzyme. With allosteric enzymes, inhibitors or activators, also known as effectors or regulator molecules, actually bind to a different site on the enzyme. This changes the structure of the enzyme, consequently altering its function.
When an inhibitor binds to an allosteric enzyme, the enzyme is effectively turned off and no longer able to function in the body. Activators, on the other hand, turn the enzyme on so that it can perform a function. The regulator molecules can detach as needed. Using this system, cells can regulate the activity of enzymes in response to changing situations, activating enzymes as needed and deactivating them when it does not want them to work.
The binding site where a regulator molecule attaches is known is known as the allosteric site on the enzyme. Allosteric regulation of enzymes involves a number of different molecules that can fit on this site, much like keys fit into a lock. With inhibition, the enzyme is maintained so that it will be ready when needed, but won't function before it is required, and with activation, it is kicked into gear so that it can perform a desired metabolic function. The body balances the numbers of active and inactive enzymes to modulate a wide variety of biological processes.
In addition to being used by the body, allosteric enzymes can also be harnessed by a doctor. Targeting the binding site on one could allow for unique drug delivery to change the shape, and therefore the function, of an enzyme. Allosteric modulation could be used to treat a number of medical conditions with precisely targeted therapy that may cause fewer side effects and other problems because it focuses on a specific enzyme within the body, rather than targeting a broad region.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a All The Science researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.