Drug targets are usually proteins, but can also be RNA, DNA, or complex carbohydrate molecules, that are specifically interacted with by drugs, resulting in a change in their behavior or function. Drugs work by binding to these targets and modifying the biochemical pathways involved in disease processes. This can lead to the elimination or control of the symptoms caused by these diseases.
Here are a few classes of drug targets:
Enzymes: Enzymes are proteins that accelerate chemical reactions in the body. Drugs may inhibit or stimulate the action of specific enzymes, altering the rate of these reactions.
Receptors: Receptors are proteins found on the surface of cells or inside cells, and they interact with specific molecules (ligands). Drugs can either mimic the action of the natural ligand by activating the receptor (agonists), or they can block the action of the natural ligand by inhibiting the receptor (antagonists).
Ion Channels: These are proteins that allow ions (like calcium, potassium, and sodium) to pass in and out of cells. Some drugs can block or enhance the flow of ions through these channels, thereby affecting the cell's function.
Nucleic Acids: These include DNA and RNA. Drugs targeting these molecules can interfere with the replication, transcription, and translation processes that are essential for cell growth and function. This type of drug target is particularly important in diseases like cancer and viral infections.
Transporters: Transporters are proteins that move substances across cell membranes. Drugs can interact with transporters to inhibit or enhance the movement of these substances.
Immunomodulators: Some drugs act by modulating the immune system. They can target various immune cells or cytokines, proteins that are involved in cell signalling in the immune system.
In drug discovery and development, one of the first steps is often to identify a potential drug target related to a particular disease. After the target is identified, researchers design or discover molecules that can interact with it effectively. These molecules are then further tested and refined to maximize their efficacy and minimize their side effects, ultimately leading to clinical trials in humans.