quantitative drug-receptor interactions Flashcards
what has to be assumed to quantify drug-receptor interactions
-law of mass action
-a negligible amount of the drug is actually bound
-the reaction is at equilibrium, forwards rate= backwards rate
what is the langmiur equation
r (fractional occupany) = [D] (drug conc)/ [D] (drug conc) + Kd
when is the langmiur equation valid
when the reaction is a simple bimolecular interaction between drug and receptor
what shape curve do you get when you plot log concentration by fractional occupancy
sigmodial
if an agonist binds to a g-protein-linked receptor, what will happen to the affinity of the receptor
it will decrease
what is positive cooperativity
where the binding of a substrate to a receptor makes it easier for the second by increasing the affinity of the receptor
what is negative coopertivity
where the binding of a substrate makes it harder for the second one to bind by decreasing the affinity for the receptor
what does the hill coefficient show us
the type of cooperativity or if it is a simple interaction
what shape is a graph that is fractional occupant against concentration
rectangular hyperbola
what does the occupation theory state
the response is directly proportional to the number of receptors occupied
what is the pD2
the negative log of the agonist concentration that gives a half-maximal response
what does pD2 quantify
the affinity of an agonist for its receptor
if a drug has a high pD2 value what does this mean
it acts at low concentrations
what is the issue with pD2
the assuptions are not always correct meaning the drug may appear to bind more tightly
