[Dioxin-l] Single molecule and statistics

[david bell]

Hi Bill

one of the things you do to test how 'fatty' a compound is is to mix it with 
water, and octanol- a fatty alcohol. You then measure how much compound is 
in the water, and how much in the octanol, and this gives you a measure of 
how much the compound prefers fats. For dioxins, I have seen coefficients of 
100,000 to 10,000,000 quoted. This underestimates the effect seen in cells, 
which are a salty water solution- this would have the effect of driving even 
more dioxin into a 'fatty' compartment.

So to answer, dioxin simply prefers to dissolve in cellular lipids (cell 
membrane, nuclear memrane, ER, etc): it is not specifically bound, so much 
as dissolved. The other thing that keeps dioxin in solution is proteins; 
many proteins have very 'fatty' pockets, and the interior of most proteins 
is very 'fatty', and so dioxin associates well with these fatty 
environments.

The other thing is that dioxin is not attached to these environments; it is 
free to diffuse out of the fat at any time.

cheers
david

>Several issues: 1) dioxin is highly insoluble in water, and so most dioxin 
>in a cell will be in in cellular lipid, or bound to a hydrophobic site- it 
>won't be available

>David, when you say "will be in cellular lipid", how does it attach >there. 
>Does it attach to a low-density lipoprotein? Or just exactly >how?
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