transporter proteins - J penny Flashcards
where are proteins located?
in the plasma membrane
what do uptake transporters do?
they transport substrates into cells
what do efflux transporters do?
pump substrates out of cell
what is the mechanism of efflux transporters?
active transport - uses ATP as an energy source
- they transport substrates against a conc gradient
what do ABC transporters stand for?
Atp binding cassette
how do efflux transporters look in the membrane?
they form a pore in the membrane
list 3 efflux ABC transporters?
P-glycoprotein, BCRP, MRP
What is the most prevalent MDR transporter?
p-glycoproteins
how do p-glycoproteins work?
Atp binds to the Nucleotide Binding Domains in order to pump the drug/toxin out of the cell
what does BCRP protein stand for?
Breast Cancer Resistance Protein
efflux transporters can affect drug…
ADME. absorption, distribution in tissues/organs, metabolism, excretion. i.e pharmacokinetics
when a drug is absorbed orally, where is it first absorbed into?
small intestine
where are p-gp, BCRP expressed in?
apical membrane of intestinal epithelial cells
name some drugs p-gp’s reduce absorption of?
digoxin (heart failure) and cyclosporin A
how are drugs excreted from the body?
via liver, via kidney
