<p>I'm wondering exactly how ligands bind to and release from receptors. Until recently I presumed ligands were attracted to receptors through electrostatic forces with no chemical interaction involved, and that catabolic enzymes (MAO, AChE) were simply present in the extracellular fluid. I hadn't given much thought as to how they disengage, but assumed ligands were brushed off by the extracellular fluid. </p>

<p>However, recently, I was reading about acetylcholinergic signaling and how it can be disrupted by, and I've come to realize is that everything I thought I knew about neurotransmission may be wrong. What I've read suggests this (article linked below):</p>

<ul>
<li><p>AChE is membrane-bound</p></li>
<li><p>AChE is part of the AChR, or just happens to be is close enough proximity that the AChE can catabolize the ligand while bound to the receptor</p></li>
<li><p>The AChR attracts ACh's positively-charged amine, which brings the acetyl group within range of AChE's reactive alcohol group. This alcohol group cleaves the acetyl group from ACh</p></li>
<li><p>It is not until the acetyl group is cleaved that the ligand disengages from the receptor</p></li>
</ul>

<p>My questions:</p>

<ul>
<li><p>Is all of this correct?</p></li>
<li><p>Are the AChR and AChE distinct? If so, how can both simultaneously interact with a single molecule given their much larger size? If not, why are they ever spoken of as different?</p></li>
<li><p>Is this sort of catabolism-mediated disengagement the case with other neurotransmitters? </p></li>
<li><p>Where can I read more about this, and what is this sort of interaction called? It's been difficult finding information on this.</p></li>
</ul>

<p>Here's the source I was reading on ACh transmission:
<a href="http://www.umich.edu/~essen/html/web_mod/cobra/respiration_detailed.html" rel="nofollow">http://www.umich.edu/~essen/html/web_mod/cobra/respiration_detailed.html</a> </p>

CC BY-SA 3.0
2014-07-31T11:01:54.143Z
Look for the Coursera course "Drugs and the Brain" and see when it's offered next.  It touches on a lot of these issues and more, and I think you would find it fascinating.  Meanwhile, I'll see if I can answer some of this a bit later.
Chuck Sherrington
CC BY-SA 3.0
2014-07-31T11:03:05.563Z
[This](http://www.amazon.com/Molecular-Neuropharmacology-Foundation-Clinical-Neuroscience/dp/0071481273/ref=sr_1_1?ie=UTF8&qid=1406804539&sr=8-1&keywords=molecular+neuropharmacology+a+foundation+for+clinical+neuroscience&dpPl=1) is the text used in the course.  It's gone up a lot in price, but it's very helpful.
Chuck Sherrington
CC BY-SA 3.0
2015-04-18T13:41:12.033Z
I'm voting to close this question as off-topic because it's a biology question.
Christian Hummeluhr
CC BY-SA 3.0
2015-04-18T17:31:41.560Z
@ChristianHummeluhr normally I would be inclined to agree with you, but Chuck's comment suggests that this could be a border-case between bio and our site.
Artem Kaznatcheev
CC BY-SA 3.0
2015-04-19T07:36:08.803Z
@ArtemKaznatcheev That's what close votes are for, I suppose, but it doesn't seem to have anything to do with any behavioral variables at all, so I'm maintaining my vote. I might have been more inclined to agree if Chuck or another trusted user had attempted an answer rather than a quick comment.
Christian Hummeluhr
CC BY-SA 3.0
2015-04-23T00:34:26.837Z
@ChristianHummeluhr I've been pretty busy over the last couple of years.  I can't promise I will be able to answer at this time, but I think questions like these should be "grandfathered" in.  While I respect and admire the work that you've put into the site thus far, the Area 51 numbers aren't everything.
Chuck Sherrington
CC BY-SA 3.0
2015-04-23T06:42:56.423Z
@ChuckSherrington Thank you, and likewise. The close vote failed; let's leave it at that. :)
Christian Hummeluhr
CC BY-SA 3.0
2015-04-23T07:00:36.660Z
Maybe @AliceD can take a look? This is not really something I can answer.
Christian Hummeluhr
<neuroscience><cell-signaling>
How do ligands bind to and release from receptors?
untitled
# How do ligands bind to and release from receptors?

(Asked by: username_0 on 2014-07-31)

I'm wondering exactly how ligands bind to and release from receptors. Until recently I presumed ligands were attracted to receptors through electrostatic forces with no chemical interaction involved, and that catabolic enzymes (MAO, AChE) were simply present in the extracellular fluid. I hadn't given much thought as to how they disengage, but assumed ligands were brushed off by the extracellular fluid.

However, recently, I was reading about acetylcholinergic signaling and how it can be disrupted by, and I've come to realize is that everything I thought I knew about neurotransmission may be wrong. What I've read suggests this (article linked below):

* AChE is membrane-bound
* AChE is part of the AChR, or just happens to be is close enough proximity that the AChE can catabolize the ligand while bound to the receptor
* The AChR attracts ACh's positively-charged amine, which brings the acetyl group within range of AChE's reactive alcohol group. This alcohol group cleaves the acetyl group from ACh
* It is not until the acetyl group is cleaved that the ligand disengages from the receptor

My questions:

* Is all of this correct?
* Are the AChR and AChE distinct? If so, how can both simultaneously interact with a single molecule given their much larger size? If not, why are they ever spoken of as different?
* Is this sort of catabolism-mediated disengagement the case with other neurotransmitters?
* Where can I read more about this, and what is this sort of interaction called? It's been difficult finding information on this.

Here's the source I was reading on ACh transmission:
<http://www.umich.edu/~essen/html/web_mod/cobra/respiration_detailed.html>

**Tags:** neuroscience, cell-signaling

> **Comments:**
> **username_1**: Look for the Coursera course "Drugs and the Brain" and see when it's offered next.  It touches on a lot of these issues and more, and I think you would find it fascinating.  Meanwhile, I'll see if I can answer some of this a bit later.  
> **username_1**: [This](http://www.amazon.com/Molecular-Neuropharmacology-Foundation-Clinical-Neuroscience/dp/0071481273/ref=sr_1_1?ie=UTF8&qid=1406804539&sr=8-1&keywords=molecular+neuropharmacology+a+foundation+for+clinical+neuroscience&dpPl=1) is the text used in the course.  It's gone up a lot in price, but it's very helpful.  
> **username_2**: I'm voting to close this question as off-topic because it's a biology question.  
> **username_3**: @ChristianHummeluhr normally I would be inclined to agree with you, but Chuck's comment suggests that this could be a border-case between bio and our site.  
> **username_2**: @ArtemKaznatcheev That's what close votes are for, I suppose, but it doesn't seem to have anything to do with any behavioral variables at all, so I'm maintaining my vote. I might have been more inclined to agree if Chuck or another trusted user had attempted an answer rather than a quick comment.  
> **username_1**: @ChristianHummeluhr I've been pretty busy over the last couple of years.  I can't promise I will be able to answer at this time, but I think questions like these should be "grandfathered" in.  While I respect and admire the work that you've put into the site thus far, the Area 51 numbers aren't everything.  
> **username_2**: @ChuckSherrington Thank you, and likewise. The close vote failed; let's leave it at that. :)  
> **username_2**: Maybe @AliceD can take a look? This is not really something I can answer.  

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## 0 answers

