[gmx-users] OPLS C-terminal Capping of Glu residue a bug?

[Marco Ceruso]

Hi-
I was generating the topology for a protein with a Glu residue at the
C-terminus and I got an absurd total charge of -0.13
It appears that the charge on the C-alpha atom is the culprit. When inside
the protein the Ca of Glu is opls_224B with a charge of 0.14, at the
C-terminus pdb2gmx labels the Glu as opls_285 with a charge of -0.09.
Looking at other topologies the last residues has an opls_283 for Ca with a
charge of 0.04, which seems to be the correct charge.
Marc