L1- How drugs are discovered Flashcards
What controls the selective permeability of ion channels?
The selectivity filter. Selects ions based on charge and size.
How does the selectivity filter work?
There’s a ring of amino acids with the opposite charge to the ion it selects for. This repels wrongly charged ions. The ions must also be the perfect size for the channel.
WHat subunit structure does the G protein have?
alpha, beta and gamma. the alpha splits off from the other two.
Which neurotransmitter is the major inhibitory one in the CNS?
GABA
How many subunits do nicotinic receptors have?
Five
Is glucocorticoid receptor a cell surface protein?
No it’s a cytosolic protein that translocates to the nucleus upon bindin agonists.
Which G proteins does adenylate cyclase link to?
Gs and Gi. s=stimulatory
i-inhibitory
What is IP3 linked to?
Gq. Ip3 is a second messenger produced in the phospholipase C pathway.
What is phospholipase C linked to?
Gq (like in lab report)
What enzyme activity do G proteins have?
The y have built in GTPase enzyme activity
Before entering the nucleus, what must nuclear hormone rececptors do? 3 things
- Bind with ligand
- Dissociate from heat shock proteins
- Dimerize
What is transactivation?
The process by which nuclear hormone receptors increase the expression of a protein
What is an orphan receptor?
A receptor for which the endogenous liigand is not known
What’s teh structure of a ligand gates ion channel? (e.g. nicotininc actylcholine receptor.)
- 4 TM domains
- N terminus extracellular
- Large loop between TM3 and TM4.
- TM2 forms the lining of the channel
Whats the structure of GPCRs?
7 transmembrane domains
The N terminus is extracellular
Large loop between TM5 and 6
