[gmx-users] Re: bilayers move apart by nanometers upon implementing dihedral restraints on lipid tails

[Dr. Vitaly V. G. Chaban]

>
> I am trying to change all lipid acyl tails to a trans orientation, and
> thought that restraining all tail dihedrals to 180 should work quickest. I
> have also tried smaller angles (120, 100) and the effect is the same,
> leaflets drifting apart.
>
> In fact, the 180 restraint does work fine in vacuo for a single lipid. But
> it is possible that the restraints are too loud. I will play with this for a
> little bit.
>
> The dihedrals of ALL lipid acyl tails in a typical lipid bilayer are being
> restrained.
>

If the force field is coarse-grained, can the problem perhaps be
caused by the inconsistency between the restraint force constant and
the time-step?

Vitaly


Dr. Vitaly V. Chaban, 430 Hutchison Hall
Dept. Chemistry, University of Rochester
120 Trustee Road, Rochester, NY 14627-0216
THE UNITED STATES OF AMERICA