TCAs and receptor affinity?

[blueboyscholar]

---

Members don't see this ad.

Does anyone know how one molecule can inhibit so many different receptors? The whole lock and key idea doesn't work here, considering that TCAs inhibit H1 receptors, muscarinic receptors, alpha-1 receptors, etc...

 

[justaregularmed]

Does anyone know how one molecule can inhibit so many different receptors? The whole lock and key idea doesn't work here, considering that TCAs inhibit H1 receptors, muscarinic receptors, alpha-1 receptors, etc...

Google their structures, espcially http://en.wikipedia.org/wiki/File:Iprindole-structure.png

I dunno to me I can see how this could block stuff up, kinda similar.

Look at epinephrine compared to that.

 

[Step1Hash]

Does anyone know how one molecule can inhibit so many different receptors? The whole lock and key idea doesn't work here, considering that TCAs inhibit H1 receptors, muscarinic receptors, alpha-1 receptors, etc...

It's possible it does it via different binding sites, like how an antigen can have different epitopes

 

[blueboyscholar]

It's possible it does it via different binding sites, like how an antigen can have different epitopes

that is kind of what I was leaning twd..TY

 

[justaregularmed]

Structure = Function.

This is Iprindole a TCA ^

This is Serotonin^

This is Epinephrine -

Serotonin binding site : http://www.jbc.org/content/277/19/17170/F2.large.jpg

Do you see how this could get in and gum up the works? Not magic. You see that they have 4 steps in how serotonin binds eventually that big extra ring is going to keep stuff from working properly.