[gmx-users] Topology file for amino acid

[rose rahmani]

Hi,

 I want to add NME and ACE terminals to zwitterionic amino acid like
threonine and then make an input topology file for GROMACS(.itp file) to be
compatible with (AMBER99 ff in) GROMACS.

I have tried many tutorials like(
http://sf.anu.edu.au/~vvv900/amber-tutorial/1cgh-nonstandard/) but
everytime i get confused in the middle because they are little different
from my need.
(I ask in AMBER mailing list but there is no answer)

Could you please introduce me straightforward solution or tutorial which is
most simmilar to my needs?

Best regards
-Rose