[gmx-users] g_sas dG

[xy21hb]

Dear all,


I just wanna calculate the SAS of a protein (ubiquitin) in a protein-in-water binary system,
when I use g_sas, it asks me for a caculation group and output group,
I chose the whole protein as both groups.

However, the solvation free energy (dG) is positive and a bit large, ~ +300 KJ/mol,
I would imagine solvating a protein, in general, should stabilize the protein.
Is that true and how accurate is the dG compared to that from other methods lsuch as thermal integration, ...? 

Thanks,