How to calculate the free energy of different conformations of protein using mmpbsa

GROMACS version: 2021.2
GROMACS modification: No
Here post your question
Hi everyone, I have recently been using gromacs to simulate the dynamics of different conformations of proteins and need to compare the free energy of the two conformations, but it is difficult for me to use an enhanced sampling method for this system. Because I just want to qualitatively compare the free energy, I want to use mmpbsa method. But seeing that most current approaches deal with the problem of calculating protein-ligand binding energy. So I would like to ask if there are tools or tutorials for that. Anything will help!