Can you guys help me out with this?
Studies have shown that GTP analouges decrease the high affinity binding sites in binding assays. However, would'nt GTP coupling enhance high affinity state?
In my binding experiments I have a Kd of 14nM for my receptor "A", however,when I co-transfect a component "b" (which is a partner of receptor "A"), with my receptor " A", the Kd is 0.5nM and there is no change in potency (Ec50)!
Post doc in my lab says that my component B is possibly preventing GTP disassociation from the receptor "A"..
Is this a valid argument? does'nt the GTP binding itself dissociate the G-protein from the receptor?