[gmx-users] PRODRG server

Justin A. Lemkul jalemkul at vt.edu
Mon Jan 24 15:47:34 CET 2011



mohsen ramezanpour wrote:
> Thanks for your guidance.
> I looked that file,But I think the name of functional groups are 
> different in .rtp file because I can't find no one of them in this file.
> 

Functional group names are not in the .rtp files.  You locate applicable 
functional groups by knowing the residues in which they occur.

> please let me know how can I know the correct name f or functional groups
> for example:HYDROXYL,CARBOXYL,HALO,AMINO and ...
> 

All of these except halogens exist in common amino acids.  If you have many 
non-standard groups (i.e. those that don't typically occur in biomolecules), 
then perhaps your choice of force field was a poor one.  As Mark said, don't 
presuppose the solution.

-Justin

> Thanks in advance for your help
> 
> On Mon, Jan 24, 2011 at 4:01 PM, Justin A. Lemkul <jalemkul at vt.edu 
> <mailto:jalemkul at vt.edu>> wrote:
> 
> 
> 
>     mohsen ramezanpour wrote:
> 
>         Dear  Dr.justin
>         Actually by doing this  we are using two different force fields
>         in one simulation.
>         I had done it before and the result was that I discussed before
>         in gmx-users(LINCS Error,Exploding system,Bad contacts between
>         atoms)
>         Then,this approch seems to doesn't work about my system.
> 
>         Then I  want to find charges and charge groups for gromos 43A1
>         and replace them for my drug(to edit PRODRG file manually) and
>         work totally in gromos 43A1.
> 
> 
>     Please keep your story consistent.  In the last message, you said
>     you wanted to work completely within 53A6, so I advised you on how
>     to do that, now you say that you're trying to work completely within
>     43A1.
> 
> 
>         Unfortunately I can't obtain these parameter.
> 
> 
>     You certainly do have these parameters.  43A1 is part of the Gromacs
>     installation; in the .rtp file you'll find all of the functional
>     groups that were derived in 43A1, as applied to amino acids and a
>     few other groups.
> 
> 
>         Please let me have if you have it.
>         Can I use some Ab Initio software for determining partial
>         charges of my drug?
>         for example ABINIT or Gaussian!
> 
> 
>     My paper that you said you read has discussion and recommendations
>     on this point.  But be very clear: none of the QM methods we tested
>     were able to reproduce the charges that are assigned to known
>     functional groups since the Gromos parameterization methodology
>     calls for "empirical refinement."  Thus, manual modification and
>     thorough validation are always necessary.
> 
>     -Justin
> 
>         Thanks in advance
> 
> 
>         On Sat, Jan 22, 2011 at 8:03 PM, Justin A. Lemkul
>         <jalemkul at vt.edu <mailto:jalemkul at vt.edu>
>         <mailto:jalemkul at vt.edu <mailto:jalemkul at vt.edu>>> wrote:
> 
> 
> 
>            mohsen ramezanpour wrote:
> 
>                Ok
>                then,I can use  PRODRG server to generate .top and .gro files
>                for drug.
>                since it's reported charges are not very accurate ,we can
>                replace all charges completely with them in 53A6(if was
>         present).
>                But it means we are working in 53A6 force field.
>                then,we must generate .top and .gro files for our protein
>         with
>                53A6 too.
>                and work completely with 53A6.
>                Am i right?
>                thanks in advance
> 
> 
>            That sounds like a reasonable approach.  Be sure to validate the
>            drug topology.  In my experience, this procedure is pretty
>         good, but
>            you always have to convince reviewers...
> 
>            -Justin
> 
> 
>                On Sat, Jan 22, 2011 at 4:43 PM, Justin A. Lemkul
>                <jalemkul at vt.edu <mailto:jalemkul at vt.edu>
>         <mailto:jalemkul at vt.edu <mailto:jalemkul at vt.edu>>
>                <mailto:jalemkul at vt.edu <mailto:jalemkul at vt.edu>
>         <mailto:jalemkul at vt.edu <mailto:jalemkul at vt.edu>>>> wrote:
> 
> 
> 
>                   mohsen ramezanpour wrote:
> 
>                       Dear Justin
> 
>                       I read your articles about PRODRG server,they were
>         very
>                useful.
>                       But I have a question:
>                       are charges of functional groups and generally
>         other atom
>                groups
>                       the same in all force fields?
>                       Because you have modified charges of your molecules by
>                Gromos96
>                       53A6 while prodrg server is generating topology
>         files in
>                43A1.
>                       I want to know can I replace charges from gromos
>         53A6 or
>                other
>                       forcefields?
>                       thanks in advance
> 
> 
>                   Charges are not the same between force fields.  We did
>         our study
>                   with 43A1 since that is what PRODRG purports to
>         produce.  I would
>                   say that our recommendations carry to other Gromos force
>                fields, as
>                   well, but don't take charges from 43A1 and apply them to
>                53A6.  Be
>                   consistent within the force field.
> 
>                   The atom types produced by PRODRG are largely shared
>         between 43A1
>                   and 53A6, so if you *completely* replace all charges with
>                those from
>                   53A6, you should have a topology that is compatible
>         with 53A6.
> 
>                   -Justin
> 
>                   --     ========================================
> 
>                   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> <http://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>
>                <mailto:gmx-users at gromacs.org <mailto:gmx-users at gromacs.org>>
>                   <mailto: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>>
>                   <mailto: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
> 
> 
> 
>            --     ========================================
> 
>            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> <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>
>            <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
> 
> 
> 
>     -- 
>     ========================================
> 
>     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
> 
> 

-- 
========================================

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