Hi Since you want to use the AMBER force for your calculations, you will need to compute the RESP charges for your new residue (unprotoned TYR) and add the charges in your *rtp file. To compute the charges, you can use the RED.Server (http://q4md-forcefieldtools.org/REDS/).
It is not easy, so read the tutorials. HTH Stephane ---------------------- Dear All, I want to have one of tyrosine residues in my protein to be unprotonated. I am using amber force field for the simulation. But in aminoacid.rtp there is no entry for the unprotonated one. So I am adding it by myself in to the .rtp file. Now I am bit confused with the charge of the unprotonated one. How can I calculate the partial charges for each and every atoms in unprotonated tyrosine? Would Gaussian/SCF be a good one to deal with this matter? Should I take the tyrosine amino acid alone to calculate the charge in Gaussian ? Please suggest me the proper method(s) to calculate the charge. Thanks, Tarak ------------------------------ Message: 6 Date: Mon, 17 Sep 2012 08:08:22 -0400 From: Justin Lemkul <jalem...@vt.edu> Subject: Re: [gmx-users] visualize trajectory To: Shima Arasteh <shima_arasteh2...@yahoo.com>, Discussion list for GROMACS users <gmx-users@gromacs.org> Message-ID: <505712b6.3030...@vt.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 9/17/12 6:57 AM, Shima Arasteh wrote: > Hi , > > Which software is used to visualize a large mdrun output? For example 60 GB > trajectory file. > I think you should probably have a look at http://www.gromacs.org/Documentation/How-tos/Reducing_Trajectory_Storage_Volume before proceeding. There are several programs that will work, provided you don't exhaust the memory available on your workstation. -Justin -- ======================================== Justin A. Lemkul, Ph.D. Research Scientist Department of Biochemistry Virginia Tech Blacksburg, VA jalemkul[at]vt.edu | (540) 231-9080 http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin ======================================== ------------------------------ Message: 7 Date: Mon, 17 Sep 2012 08:10:27 -0400 From: Justin Lemkul <jalem...@vt.edu> Subject: Re: [gmx-users] Regarding RMSD graph nalysis To: Discussion list for GROMACS users <gmx-users@gromacs.org> Message-ID: <50571333.1060...@vt.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 9/17/12 7:02 AM, naga sundar wrote: > Dear gromacs users > > I run 20 ns MD simulation for protein mutant complexes. In RMSD analysis > at ~9 ns sudden increase in the deviation was observed from 0.2 nm to 1.7 > nm and immediate fall was observed. > > I rerun the 20 ns simulation for the same molecule with same procedure. > While analyzing the RMSD sudden increase in the deviation was observed (0.2 > nm to 1.7 nm) at the simulation period of ~12 ns. > > So i want to know the reason > > For sudden rise and fall in RMSD values. > > Next, in first MD run this deviation was observed at ~9 ns (0.2 nm to 1.7 > nm) but while rerun the molecule with same procedure this deviation was > observed at ~12 ns. > It sounds to me like your trajectories haven't correctly accounted for periodicity. g_rms does not elegantly handle sudden jumps across the box. You will need to work with trjconv. Usually a simple trjconv -pbc mol -ur compact -center does the trick for a simple protein, but for complexes it is often more difficult. http://www.gromacs.org/Documentation/Terminology/Periodic_Boundary_Conditions#Suggested_trjconv_workflow -Justin -- ======================================== Justin A. Lemkul, Ph.D. Research Scientist Department of Biochemistry Virginia Tech Blacksburg, VA jalemkul[at]vt.edu | (540) 231-9080 http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin ======================================== ------------------------------ Message: 8 Date: Mon, 17 Sep 2012 21:48:23 +0900 From: Rajiv Gandhi <graji...@gmail.com> Subject: Re: [gmx-users] Resuming of calculation from last *.cpt To: Discussion list for GROMACS users <gmx-users@gromacs.org> Message-ID: <capen9rxbkuf7mzjt8usbzreshwd9amrixh7xbp97ogtdzsb...@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Dear all, I have read few papers regarding the photo dissociation event such as Myoglobin heme-ligand bond deletion to induce the photodissociation in MD simulation. Could you please tell me the procedure how can i perform the photodissociation mechanism in Gormacs and which force field have to use, Also I want to study Upon the photo dissociation their structural changes in MD. Thanks in advance, Regards Rajiv ------------------------------ -- gmx-users mailing list gmx-users@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! End of gmx-users Digest, Vol 101, Issue 48 ******************************************-- gmx-users mailing list gmx-users@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-requ...@gromacs.org. * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists