[gmx-users] Problem with generating topology file for OPLS force field for membrane protein simulation

[Parul tew]

Dear GMX users,

I am working on a protein which I want to simulate in a lipid bilayer
environment (POPC) and want to use OPLS force field for the same. I have
previously rum the membrane protein simulations using 43a6 force field with
the help of justin's tutorial which had run quite fine. But I am having
problems for generating a topology file for OPLS ff to incorporate both
lipid and protein's topology. As the OPLS ff only contains atomtypes in
ffoplsaanb.itp file only contains the atom types, I am not able to make out
what necessary changes to follow to generate a topology file incorporating
both lipid and protein.
lso the POPC  lipid.itp (acquired from university of calgary website) is
quite different from the default ffoplsaanb file so I was wondering if
there is source to get the OPLS force field parameters for lipids.

Thanking you,
Parul Tewatia