[gmx-users] how to turn on constraints in CHARMM-GUI generated Gromacs setup?

[Victor Ma]

hello Gromacs users:

I am using the CHARMM-GUI to generate a membrane-protein system for me
which is really convenience. But I am not sure that if the constraints are
on in my simulation. I am using the default .mdp files generated from
CHARMM-GUI interface.
So the .mdp file says,
define                  = -DREST_ON -DSTEP6_0

And at the bottom of the PROA.itp and POPC.itp, they say,
#ifdef DREST_ON
#include "PROA_rest.itp"
#endif

And both PROA_rest.itp and POPC_rest.itp are present in the work directory.
It all looks fine. But when I check the output files, such as md.out and
*.log files, I don't see anything on the constraints. So I suspect that
it's off. How do I turn it on?

Another question is that is it ok to just run the system starting from
303K, which is the default setup out of ChARMM-GUI? I thought for
membrane-protein system, we are supposed to first slowly heat up the system
from 0 K to the target temperature.

Thank you so much.


Victor