inhibiitori

Inhibitori (inhibiitori in Romanian) are substances that decrease the activity of biological targets such as enzymes and receptors, thereby slowing or blocking biochemical reactions and signaling pathways. They can be natural, such as metabolic products, or synthetic, and are widely used in research and medicine to probe function and treat disease.

Enzyme inhibitors are typically classified by mechanism into reversible and irreversible categories. Reversible inhibitors bind non-covalently and may be competitive (binding to the active site and blocking substrate), non-competitive (binding elsewhere and reducing maximum velocity), uncompetitive (binding the enzyme-substrate complex), or mixed. Irreversible inhibitors form covalent bonds or very tight associations that permanently disable the enzyme; examples include aspirin acting on cyclooxygenase and penicillin inhibiting bacterial transpeptidase.

In pharmacology and medicine, inhibitors are used as drugs, such as statins (HMG-CoA reductase inhibitors) to lower cholesterol, HIV protease inhibitors to limit viral replication, and acetylcholinesterase inhibitors to treat Alzheimer’s disease. Inhibitors can also target receptors, transporters, or other signaling proteins, providing tools for research and therapeutic intervention.

Key concepts in their study include the inhibition constant Ki, the half-maximal inhibitory concentration IC50, and qualitative or quantitative plots used to characterize mechanisms (such as Lineweaver-Burk and Dixon plots). The choice of inhibitor type influences drug design, efficacy, and safety, and inhibitors often require careful consideration of dosing and potential off-target effects.