Drug receptors Flashcards
Five classes of receptors
- Intracellular
- TK
- Cytokine
- Ion channels
- G-protein
Intracellular receptors must be
lipophilic
Example of drugs that bind to lipophilic receptors
T4
Vit D
Cortisol
not easily transported in the blood -needs protein
Intracellular receptors are inactive in
cytoplasm and active when ligand binds
Drugs that bind to intracellular receptors requires time to
take effect
Sequence of TK receptors
- Binding of ligand to extracellular domain
- Sub domains dimerize
- TK self phosphorylates
- Then TK phosphorylates down stream proteins for further signaling.
Examples of things that bind to TK receptors
- Insulin
- EGF
- Atrial natriuretic peptide
Tyrosine kinase receptors and cancer
Overstimulation of EGF is thought to lead to cancer. These TK receptors can be blocked with monoclonal antibodies, which make the receptors dysfunctional. The antibodies bind to the extracellular domain because they would be impossible to go through the cell.
Adding elements such as a Chloride ion or Fluoride ion can
increase lipophilicity of a molecule
Cytokine receptors
Similar to TK receptors, but different in the fact that the intracellular domains actually recruits a TK from the cytoplasm that works as a TK through dimerization. The intracellular domain is not TK itself, but through dimerization can cause structural changes to intracellular domain that leads to the recruitment of molecules that work as TK to phosphorylate other proteins.
Examples associated with cytokine receptors
- GH
- Interferon
- Erythropoietin
Ion channels
two main subtypes
- Ligand gates
- Voltage gated
Ligand gated ion channels
The receptor is a pore surrounded by transmembrane proteins. For the pore to open, there must be a molecule to bind to one of the proteins for a certain ion to get into the cell.
Example of ligand gated ion channel that allows that passage of cations
Nicotinic receptors
Nicotinic receptors, what they use and how they work
Binds Ach and allows the influx of either sodium or calcium which leads to the depolarization of the resting potential. There are two types of nicotininc receptors, homo and heteromeric. Homo is 5 alpha whereras hetero is alpha and beta.