Lecture 2 - How Drugs Bind to Their Targets Flashcards
receptors located inside the cell
intracellular receptors
in order for a drug to bind to an intracellular receptor, it must be capable of ____
crossing the plasma membrane
in order to cross the plasma membrane, a drug must be ____
lipid soluble or have another sort of transport mechanism
a classic example of a drug which binds to an intrecellular receptor
steroid hormones
what is the mode of action of steroid hormones?
- bind to the ligand binding domain (LBD) of the receptor
- heat shock protein released
- DNA recognition region exposed
- receptor enters the nucleus and binds DNA
- activates transcription of proteins
what type of receptors are G-protein coupled receptors (GPCRs)?
transmembrane receptors
receptors where ligands bind to the extracellular side, triggering a conformational change taht activates a signalling cascade mediated by intracellular G-proteins
GPCRs
activation of GPCR promotes ___ exchange of the ___
GDP-GTP, heterotrimeric G-protein
has GTPase activity that acts like a molecular ‘timer’ to terminate the signal
G-alpha subunit
after GTP is hydrolyzed, the inactivate G-protein complex ____
reassembles and the system can reset
influence the activity of a variety of protein types including ion channels
G-beta/gamma
GPCRs are usually categorized based on ___
the subtype of G-alpha that is associated
receptors coupled to Gs trigger increased activity of ___, leading to production of ___, which activates ___
adenylate cyclase (AC), cyclic AMP (cAMP), protein kinase A (PKA)
some receptors are coupled to Gi, which ___
suppresses AC activity
receptors coupled to Gq trigger increased activity of ___, leading to the breakdown of ___ causing the production of ___, which triggers the release of intracellular ___
phospholipase C (PLC), PIP2, inositol triphosphate (IP3), Ca++
