[gmx-users] area for DOPC bilayer

[Justin MacCallum]

Hi Lanyuan,

I am part of Peter's group of have used the DOPC model you refer to
extensively. I would expect that you have not made any mistakes with your
itp file. I also get an area of ~0.67nm^2 per lipid. I don't know about any
of the other atomistic force fields, so I can't comment. It is also worth
pointing out that S.J. Marrink's coarse-grained model also gives a value in
that range as well, and it is parameterized independently. They were also
working on lipids based on the latest GROMOS parameters, although I have not
seen any results on DOPC yet. Perhaps someone can comment?

In summary, there does seem to be a large difference between the simulations
and experiment, although I don't know that anyone knows why.

Justin

Justin MacCallum
PhD Student
Department of Biological Sciences
University of Calgary
Phone: (403) 220-6869
Web: http://moose.bio.ucalgary.ca

> Hello,
> I'm just wondering if anyone did a DOPC bilayer simulation based on 
> Tieleman's parameters. I got an area per headgroup much smaller than the 
> experimental value (around 67 anstrom^2). I'm not sure whether it's due
the 
> force field or some mistakes when making the *.itp file. The itp file I 
> used is just a modification based on the POPC itp file on Tielman's 
> website. From literature I also found DOPC forcefiled from Chiu and Scott,

> and from the CHARMM. Can anyone give a comment for the different force 
> fields?
> Btw, anyone know the experimental A for full hydrated POPC bilayer?
> Thanks a lot.
> Lanyuan Lu