The phenomenon of enzymatic catalysis occupies an essential position in organic life, impossible without enzymes. An enzyme’s function is closely related to its structure because the protein’s active state should be compatible with its substrate for the reaction to occur at an accelerated speed. In fact, enzymes play a critical role in reducing the free energy of a process, thereby lowering the activation energy barrier to pull the process forward to the product side. Thus, enzyme structure and function are closely associated, making them vulnerable to inhibition, which can be reversible and irreversible.
Reversible inhibitors may bind to the enzyme’s allosteric site, causing a conformational change, which can be reverted once the foreign ligand is removed. Irreversible inhibition results from an occupation of an enzyme’s active site by an inhibitor, leading to permanent structural alteration and termination of its function. Inhibitors vary in nature, ranging from extrinsic molecules to reaction products. Overall, the two common features of all inhibitors are structural relatedness to a specific enzyme and the ability to halt the catalyst’s function.