3
$\begingroup$

I know that there are flipases and flopases that facilitate this sort of thing, but I'm curious about other possible influences. Can the Donnan effect be reversed so that phospholipids follow ions? For example, calcium efflux from cells causes it to be more energetically favorable for phosphatidylserine (slightly more negative, and thus slightly more likely to follow a positive charge) to be ejected from inner to outer leaflet.

| improve this question | |
$\endgroup$
  • 1
    $\begingroup$ While moving lipids to match charge could work, I don't know about any examples. Lipids are large and flipping rates tend to be slow. My guess is that ions can react to lipid distribution faster than lipids can react to ion distribution. $\endgroup$ – user137 Oct 2 '14 at 15:51
  • 1
    $\begingroup$ Yea, i suppose, though membrane biophysics is still a mystery to me... Perhaps the flipases/flopases make it more energetically favorable for lipids to follow the ions and not just the reverse... $\endgroup$ – Jasand Pruski Oct 2 '14 at 16:28
  • 1
    $\begingroup$ Flippases would increase flipping rate, but there are plenty of ion channels that would increase the rate at which ions can move back and forth across the membrane too. $\endgroup$ – user137 Oct 2 '14 at 16:35
  • $\begingroup$ I am refering to apoptosis, platelet activation, and any other scenario where phosphatidylserine moves from inner to outer layer... in these scenarios there is also a calcium influx... I can't help but wonder if there is a connection... $\endgroup$ – Jasand Pruski Jun 5 '15 at 23:27
  • 1
    $\begingroup$ I'm confused about what this question is actually asking. The title is unclear and the only actual question is can the donnan effect be reversed so phospholipids follow ions. $\endgroup$ – James Jun 10 '16 at 7:37