Hi all,
it seems hard to find papers showing cell plasma membrane composition change induced by drug or biological process will alter the passive permeability in vivo. What I have got are--
1. peroxidation of cell membrane has no effect on passive permeability.
2. cancer cells' membrane composition is different with normal ones, which is one of many cases that biological process reshapes membrane composition. But unclear is how much will the aforementioned change in membrane composition alter passive permeability.
3. Polarity and pore size of membrane are two main factors that matters.
Could you guys give me more info related?
best,
J
Hi Jiyuan,
The answer is yes, the membrane composition of course regulates the plasma membrane permeability. For an example, the membranbe made up of PE molecules is less permeable than that with PC molecules (Ref. 2), considering same lipid chain (DM). Although I am not an expert in in-vivo measurements, I can suggest you some novel papers that reported the fact in details. Specifically, if you go through some publications of Prof. Michael L. Klein (https://scholar.google.com/citations?user=56ar4-cAAAAJ), it would be much clear. However, you can also go through the papers below:
1. http://www.pnas.org/content/101/13/4431.full
2. http://iopscience.iop.org/article/10.1209/0295-5075/118/58002/meta
3. http://www.jbc.org/content/271/20/11627.full
4.
Article Membrane composition and ion-permeability in extremophiles
5. https://books.google.de/books?hl=en&lr=&id=kMvYBAAAQBAJ&oi=fnd&pg=PP1&ots=VwMKmlwGKT&sig=pPc0CPoPjQPINBgNxy5ulcXVvMU&redir_esc=y#v=onepage&q&f=false
Best wishes,
Rajendra
which types of compounds are you interested in ? Passive diffusion also depends on the diffusing molecule so this must be taken into consideration. And suppose effects of lipid composition are stronger when it comes to small polar molecules (water and ions) than for larger hydrophobic ones. But if you look at it from a “black box” point of view, flux (mass transported per area per time) is governed by Ficks law where barrier thickness and diffusion coefficient in the barrier plays a role (both can be influenced by membrane composition).
Hi Dr. Bordin,
i am looking at TPMP, methyl triphenyl phosphonium, that should be the larger hydrophobic cation.
papers said that artificial membranes with different composition have varied permeability for TPMP.
But can in vivo biological process induce so much change in membrane composition that is enough to alter its permeability in vivo?
1. regarding the aforeme biological process, I heard particular drug and special diet supplement aiming to modify membrane lipids. But what’s their modification efficiency? and has gene knock out been tried to change membrane composition?
2. Even if the in vivo membrane composition can be critically changed, can in vivo permeability change consequently? I doubt this since a thesis shows no permeabilty change even after membrane is intensely proxidized thus the author proposes unknown repairment mechanism to be revealed
I deeply appreciate if you could share more of your expertise with me on this?
Cheers
j
Hi Giri,
thanks for these valuable papers.
seems artificial membranes with different composition have varied permeability.
But can in vivo biological process induce so much change in membrane composition that is enough to alter its permeability in vivo?
1. regarding the aforeme biological process, I heard particular drug and special diet supplement aiming to modify membrane lipids. But what’s their modification efficiency? and has gene knock out been tried to change membrane composition?
2. Even if the in vivo membrane composition can be critically changed, can in vivo permeability change consequently? I doubt this since a thesis shows no permeabilty change even after membrane is intensely proxidized thus the author proposes unknown repairment mechanism to be revealed
I will appreciate a lot if you could share more of your expertise with me on this
Cheers
j
Hi Jiyuan,
As I mentioned earlier that I have no expertise in in-vivo phenomena, from the previous reports I could say that cell membrane in-vivo has the ability to change its composition, sufficient to prevent a particular cytotoxic mechanism. It's not only the composition, it can be altered by altering the lipid phase. A small change in lipid composition can result in a significant change in phase and hence in the permeability. Introducing cholesterol in the membrane is a good example for this. Presence of even a small amount of cholesterol can change the membrane permebility a lot. Also it is to be noted that the effect really varies from one type of cell to other. So, you can always see higher effect for a cell of particular type than others.
Regarding your question: "and has gene knock out been tried to change membrane composition? " Frankly speaking I have no idea on this part.
Regarding your second point, YES in my opinion. The permeability should change significantly if you critically change the membrane composition even in-vivo. But, as I said, it depends on the the cell type.
These phenomena are nicely described in the papers attached:
Best,
Rajendra
Many Thanks Rajendra. These are very helpful papers. You must be an expert in this filed.
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