Register to reply

Does tetrodotoxin look like something in the body?

by jackmell
Tags: body, tetrodotoxin
Share this thread:
jackmell
#1
Jul1-13, 07:32 AM
P: 1,666
Blue-ring octopus' have this. It binds to Na channels in nerve cells.

I don't know if you guys know this in here about biochemistry, but it includes a marvelous story of mimicry.

Anyways, I was just wondering if tetrodotoxin looks like something, in the same way that LSD looks like dopamine. Didn't say anything about mimicry in Wikipedia but they just might not know.
Phys.Org News Partner Medical research news on Phys.org
Senegal monitors contacts of 1st Ebola patient
Snacking while watching action movies leads to overeating
Quality of US diet shows modest improvement, but overall remains poor
SW VandeCarr
#2
Jul1-13, 03:47 PM
P: 2,501
Quote Quote by jackmell View Post
Blue-ring octopus' have this. It binds to Na channels in nerve cells.

I don't know if you guys know this in here about biochemistry, but it includes a marvelous story of mimicry.

Anyways, I was just wondering if tetrodotoxin looks like something, in the same way that LSD looks like dopamine. Didn't say anything about mimicry in Wikipedia but they just might not know.
What you are asking, I think, is does the body provide a natural compound that could competitively block TTX at the neurotoxic receptor site 1 (NXR1)? I doubt it, at least not in sufficient quantities that would be effective. Otherwise TTX wouldn't be so toxic. However there is a class of peptides which does bind to NXR1 and could possibly block TTX. They're are called [itex]\mu[/itex]-conopeptides and their interaction with NXR1 neurotoxins is complex, so I would stay away from the Blue Ring Octopus and other TTX making creatures for the time being. The issue isn't so much how the whole molecule looks, but how that portion of the molecule presented to the receptor site looks.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920548/
jackmell
#3
Jul2-13, 07:30 AM
P: 1,666
Quote Quote by SW VandeCarr View Post
What you are asking, I think, is does the body provide a natural compound that could competitively block TTX at the neurotoxic receptor site 1 (NXR1)? I doubt it, at least not in sufficient quantities that would be effective. Otherwise TTX wouldn't be so toxic. However there is a class of peptides which does bind to NXR1 and could possibly block TTX. They're are called [itex]\mu[/itex]-conopeptides and their interaction with NXR1 neurotoxins is complex, so I would stay away from the Blue Ring Octopus and other TTX making creatures for the time being. The issue isn't so much how the whole molecule looks, but how that portion of the molecule presented to the receptor site looks.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920548/
Hi. Thanks for that. Fascinating subject. Here's a quote:

"TTX is thought to occupy a site within the vestibule of the ion channel near the extracellular end of the channel pore, and, by binding to this site, to occlude the permeation pathway of sodium ions through the pore."

I suppose perhaps I don't understand the physiology well enough. I thought the gate was normally controlled by various molecules which open and close it and that maybe TTX, or a particular part of TTX resembled the active end of the normal molecule which closed it and had a greater affinity to the active site so thus blocked the normal agent from controlling the gate.

SW VandeCarr
#4
Jul2-13, 11:36 AM
P: 2,501
Does tetrodotoxin look like something in the body?

Quote Quote by jackmell View Post

I suppose perhaps I don't understand the physiology well enough. I thought the gate was normally controlled by various molecules which open and close it and that maybe TTX, or a particular part of TTX resembled the active end of the normal molecule which closed it and had a greater affinity to the active site so thus blocked the normal agent from controlling the gate.
The sodium channel has both a pore and a gate, although they work closely together. TTX apparently physically blocks the pore superseding the gating function. Voltage gated channels typically are selective for sodium, potassium or calcium. Ion filtering is a function of the pore. The gate closes to ion flux with inactivation of the channel as during the refractory period following an action potential.

http://jp.physoc.org/content/590/11/2577.full.pdf+html


Register to reply

Related Discussions
Rotational Kinetic Energy of Body in another body reference frame Classical Physics 9
Compare the recombination rates for 2-body and 3-body reactions (i.e. forming O2) Introductory Physics Homework 0
Is the energy conserved FOR EACH BODY in a two-body central force problem? Classical Physics 2
Derive equation of trajectory of a body around a fixed body attracted by gravity Introductory Physics Homework 2
The max height the body reaches when this body is thrown verticaly upwards Introductory Physics Homework 1