Drug- Target Interaction as Receptors
- Receptors are proteins that are crucial to body’s communication process.
- Receptor proteins are embedded in the cell membrane in such a way that their small part possessing active site projects out of the surface of the membrane and opens on the outside region of the cell membrane.
- In the body, message between two neurons and that between neurons of muscles is communicated through certain chemicals.
- These chemicals are known as chemical messengers and are received at the binding sites of receptor proteins.
- To accommodate a messenger, shape of the receptor site changes, as a result transfer of message happens into the cell.
- Thus, chemical messenger gives message to the cell without entering the cell.
- There are a large number of different receptors in the body that interact with different chemical messengers.
- These receptors show selectivity for one chemical messenger over the other because their binding sites have different shape, structure and amino acid composition.
- Drugs that bind to the receptor site and inhibit its natural function are called antagonists.
- These are useful when blocking of message is required.
- There are other types of drugs that mimic the natural messenger by switching on the receptor, these are called agonists. These are useful when there is lack of natural chemical messenger.