[gmx-users] restraints on water oxygen atoms
jalemkul at vt.edu
Mon Jun 10 14:20:55 CEST 2013
On 6/10/13 3:37 AM, Shima Arasteh wrote:
> Thanks for your reply.
> The system I am trying to equilibrate is composed of popc/ peptide/ions/water. I built the system by InflateGRO methodology as you wrote in kalp-dppc tutorial. The last gro file which gave me the acceptable APL, was used as the starting configuration in next steps. But before going on, I found some overlaps between lipids acyl chains and peptide structure. So tried to move the lipid residues caused the overlaps. Then there are some gaps between peptide and near lipid chains. As a result, I see the water cleavage in these regions.
> Would you please give me any suggestions? How would I make a better packed system without disturbing overlaps or crashes?
> Would you please help me?
Don't manually delete lipids. InflateGRO overestimates APL, so if you reach
your target value, realize that the lipids are more packed than that and the
true APL is much smaller. I discuss that fact in the KALP-DPPC tutorial. I
generally stop packing when the lipids claim to be about 10% higher than the
desired APL. If you delete lipids because you've forced them together too much,
then you're going to severely compromise the membrane.
Justin A. Lemkul, Ph.D.
Department of Biochemistry
jalemkul[at]vt.edu | (540) 231-9080
More information about the gromacs.org_gmx-users