[gmx-users] how to write a rtp file for amido amine
Justin A. Lemkul
jalemkul at vt.edu
Sat Oct 9 21:32:10 CEST 2010
lammps lammps wrote:
> Thanks for Mark and Justin's help. But I have new questions as follows:
>
>
> CYS SG 1 HEME FE 2 0.25 CYS2 HEME
>
> 1.residue name A
> 2.atom name A
> 3.number of bonds that this atom can form (does the number include
> the bonds of atom with H atoms?)
It should pertain to the number of bonds you want that atom to form, aside from
those in the .rtp entry. See the line for HIS NE2, which forms one bond to FE,
but certainly forms other bonds to atoms in the HIS residue.
> 4.residue name B
> 5.atom name B
> 6.number of bonds that this atom can form
> 7.the reference length for searching for candidate bonds, the margin is
> ±10% ( It seems the unreasonable length can result in the unexpected
> bond. does it? )
I don't understand your question. If you define a bond at, i.e. 0.1 nm, pdb2gmx
will build a bond if the distance between the two atoms is 0.9 - 1.1 nm. An
unreasonable bond will only be formed if you provide an unreasonable search
distance.
> 8.the new name for residue A ( Why new residue name?)
This isn't always relevant. Note that most of the entries in specbond.dat
remain unchanged. The only instances of the residue name changing are related
to force field-specific disulfide conventions (i.e., CYS vs. CYS2).
-Justin
> 9.the new name for residue B
>
> Thanks again.
>
>
> 2010/10/9 Justin A. Lemkul <jalemkul at vt.edu <mailto:jalemkul at vt.edu>>
>
>
>
> lammps lammps wrote:
>
> Hi Mark,
>
> Thanks for your reply. But, I do not know the meaning of the
> columns in specbonds.dat. I also do not find any information
> in the manual 4.0.
>
> Could you provide something about the specbonds.dat or give some
> explanations.
>
>
> http://www.gromacs.org/Documentation/File_Formats/specbond.dat
>
> -Justin
>
> Thanks in advance.
>
>
>
> 2010/10/9 Mark Abraham <mark.abraham at anu.edu.au
> <mailto:mark.abraham at anu.edu.au> <mailto:mark.abraham at anu.edu.au
> <mailto:mark.abraham at anu.edu.au>>>
>
>
>
>
> ----- Original Message -----
> From: lammps lammps <lammp2forum at gmail.com
> <mailto:lammp2forum at gmail.com>
> <mailto:lammp2forum at gmail.com <mailto:lammp2forum at gmail.com>>>
> Date: Saturday, October 9, 2010 19:27
> Subject: [gmx-users] how to write a rtp file for amido amine
> To: Discussion list for GROMACS users <gmx-users at gromacs.org
> <mailto:gmx-users at gromacs.org>
> <mailto:gmx-users at gromacs.org <mailto:gmx-users at gromacs.org>>>
>
> > Hi everybody,
> >
> > I want to use pdb2gmx command to create a .gro file and a .top
> file for PAMAM whose repeat unit is amidoamine ( attached ).
> >
> > /
> > ---CH2--CH2--CO-NH-CH2-CH2-N (see the attached figure)
> > \
> >
> > The atom N have two same branches with --CH2--. I write
> the rtp
> file for it as follows:
> >
> > [ atoms ]
> > C1 opls_245 -0.050 1 > .........
> > [ bonds ]
> > C1 -N7
> > .......
> > C6 N7
> > N7 +C1
> > N7 +C1
> >
> > It seems not work, which gives a wrong top structure. The
> question is how can I deal with the two branches of N. Any
> suggestion is appreciated.
>
> pdb2gmx is intended only for work with linear heteropolymers. Any
> more complex things (e.g. disulfides, branched structures)
> have to
> be engineered using the specbonds.dat mechanism.
>
> Mark
> --
> gmx-users mailing list gmx-users at gromacs.org
> <mailto:gmx-users at gromacs.org>
> <mailto:gmx-users at gromacs.org <mailto:gmx-users at gromacs.org>>
>
> http://lists.gromacs.org/mailman/listinfo/gmx-users
> Please search the archive at
> http://www.gromacs.org/Support/Mailing_Lists/Search before
> posting!
> Please don't post (un)subscribe requests to the list. Use the
> www interface or send it to gmx-users-request at gromacs.org
> <mailto:gmx-users-request at gromacs.org>
> <mailto:gmx-users-request at gromacs.org
> <mailto:gmx-users-request at gromacs.org>>.
>
> Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>
>
>
>
> --
> wende
>
>
> --
> ========================================
>
> Justin A. Lemkul
> Ph.D. Candidate
> ICTAS Doctoral Scholar
> MILES-IGERT Trainee
> Department of Biochemistry
> Virginia Tech
> Blacksburg, VA
> jalemkul[at]vt.edu <http://vt.edu/> | (540) 231-9080
> http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin
>
> ========================================
> --
> gmx-users mailing list gmx-users at gromacs.org
> <mailto:gmx-users at gromacs.org>
> http://lists.gromacs.org/mailman/listinfo/gmx-users
> Please search the archive at
> http://www.gromacs.org/Support/Mailing_Lists/Search before posting!
> Please don't post (un)subscribe requests to the list. Use the www
> interface or send it to gmx-users-request at gromacs.org
> <mailto:gmx-users-request at gromacs.org>.
> Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>
>
>
>
> --
> wende
--
========================================
Justin A. Lemkul
Ph.D. Candidate
ICTAS Doctoral Scholar
MILES-IGERT Trainee
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin
========================================
More information about the gromacs.org_gmx-users
mailing list