Answer:
An enzyme whose activity is controlled by allosteric regulation.
Explanation:
Enzymes are proteins that accelerate chemical reactions within the cell. Enzymes bind to the substrate in the active site, catalyzes the reaction, for example the breakdown of the binding molecule, and release the product or products.
The enzyme activity need to be regulated. One of the mechanisms by which this occurs involves effector molecules, usually small molecules which bind to the regulatory site, called allosteric site. The binding to effector molecules may activate or inhibit the enzyme activity, consequently increasing or decreasing the rate of the reaction.
This mechanism of enzyme control is called allosteric regulation.
The description of the protein isolated fits with this features, an enzyme whose activity is controlled by allosteric regulation.