[gmx-users] total charge (qtot)

Justin Lemkul jalemkul at vt.edu
Wed May 13 15:06:16 CEST 2015



On 5/13/15 9:04 AM, James Lord wrote:
> Dear gmx users,
> I am trying to repeat Justin's Lysozyme tutorial for 1HFX.pdb,
>
> https://drive.google.com/file/d/0B0YMTXH1gmQsUjVSd01ERXVpLTA/view?usp=sharing
>
> I would like to know the total charge of my system but I have two statement
> for that,after running
>
> pdb2gmx -f 1HFX.pdb -o 1HFX_processed.gro -water spce
>
>   one is saying -9e and 2e? I am a bit confuse can anyone tell me why it is
> like this? I also checked the topol.top and there is no "qtot"
>

You have multiple chains, each with a net charge.  The qtot value is, in fact, 
printed to the topology, just in each chain's .itp file.

-Justin

>
> pdb2gmx -f 1HFX.pdb -o 1HFX_processed.gro -water spce
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>          Peter Kasson, Carsten Kutzner, Per Larsson, Pieter Meulenhoff,
>             Teemu Murtola, Szilard Pall, Sander Pronk, Roland Schulz,
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>               of the License, or (at your option) any later version.
>
>                                 :-)  pdb2gmx  (-:
>
> Option     Filename  Type         Description
> ------------------------------------------------------------
>    -f       1HFX.pdb  Input        Structure file: gro g96 pdb tpr etc.
>    -o 1HFX_processed.gro  Output       Structure file: gro g96 pdb etc.
>    -p      topol.top  Output       Topology file
>    -i      posre.itp  Output       Include file for topology
>    -n      clean.ndx  Output, Opt. Index file
>    -q      clean.pdb  Output, Opt. Structure file: gro g96 pdb etc.
>
> Option       Type   Value   Description
> ------------------------------------------------------
> -[no]h       bool   no      Print help info and quit
> -[no]version bool   no      Print version info and quit
> -nice        int    0       Set the nicelevel
> -chainsep    enum   id_or_ter  Condition in PDB files when a new chain
> should
>                              be started (adding termini): id_or_ter,
>                              id_and_ter, ter, id or interactive
> -merge       enum   no      Merge multiple chains into a single
>                              [moleculetype]: no, all or interactive
> -ff          string select  Force field, interactive by default. Use -h for
>                              information.
> -water       enum   spce    Water model to use: select, none, spc, spce,
>                              tip3p, tip4p or tip5p
> -[no]inter   bool   no      Set the next 8 options to interactive
> -[no]ss      bool   no      Interactive SS bridge selection
> -[no]ter     bool   no      Interactive termini selection, instead of
> charged
>                              (default)
> -[no]lys     bool   no      Interactive lysine selection, instead of charged
> -[no]arg     bool   no      Interactive arginine selection, instead of
> charged
> -[no]asp     bool   no      Interactive aspartic acid selection, instead of
>                              charged
> -[no]glu     bool   no      Interactive glutamic acid selection, instead of
>                              charged
> -[no]gln     bool   no      Interactive glutamine selection, instead of
>                              neutral
> -[no]his     bool   no      Interactive histidine selection, instead of
>                              checking H-bonds
> -angle       real   135     Minimum hydrogen-donor-acceptor angle for a
>                              H-bond (degrees)
> -dist        real   0.3     Maximum donor-acceptor distance for a H-bond
> (nm)
> -[no]una     bool   no      Select aromatic rings with united CH atoms on
>                              phenylalanine, tryptophane and tyrosine
> -[no]ignh    bool   no      Ignore hydrogen atoms that are in the coordinate
>                              file
> -[no]missing bool   no      Continue when atoms are missing, dangerous
> -[no]v       bool   no      Be slightly more verbose in messages
> -posrefc     real   1000    Force constant for position restraints
> -vsite       enum   none    Convert atoms to virtual sites: none, hydrogens
>                              or aromatics
> -[no]heavyh  bool   no      Make hydrogen atoms heavy
> -[no]deuterate bool no      Change the mass of hydrogens to 2 amu
> -[no]chargegrp bool yes     Use charge groups in the .rtp file
> -[no]cmap    bool   yes     Use cmap torsions (if enabled in the .rtp file)
> -[no]renum   bool   no      Renumber the residues consecutively in the
> output
> -[no]rtpres  bool   no      Use .rtp entry names as residue names
>
>
> Select the Force Field:
>  From '/usr/local/gromacs/share/gromacs/top':
>   1: AMBER03 protein, nucleic AMBER94 (Duan et al., J. Comp. Chem. 24,
> 1999-2012, 2003)
>   2: AMBER94 force field (Cornell et al., JACS 117, 5179-5197, 1995)
>   3: AMBER96 protein, nucleic AMBER94 (Kollman et al., Acc. Chem. Res. 29,
> 461-469, 1996)
>   4: AMBER99 protein, nucleic AMBER94 (Wang et al., J. Comp. Chem. 21,
> 1049-1074, 2000)
>   5: AMBER99SB protein, nucleic AMBER94 (Hornak et al., Proteins 65,
> 712-725, 2006)
>   6: AMBER99SB-ILDN protein, nucleic AMBER94 (Lindorff-Larsen et al.,
> Proteins 78, 1950-58, 2010)
>   7: AMBERGS force field (Garcia & Sanbonmatsu, PNAS 99, 2782-2787, 2002)
>   8: CHARMM27 all-atom force field (with CMAP) - version 2.0
>   9: GROMOS96 43a1 force field
> 10: GROMOS96 43a2 force field (improved alkane dihedrals)
> 11: GROMOS96 45a3 force field (Schuler JCC 2001 22 1205)
> 12: GROMOS96 53a5 force field (JCC 2004 vol 25 pag 1656)
> 13: GROMOS96 53a6 force field (JCC 2004 vol 25 pag 1656)
> 14: GROMOS96 54a7 force field (Eur. Biophys. J. (2011), 40,, 843-856, DOI:
> 10.1007/s00249-011-0700-9)
> 15: OPLS-AA/L all-atom force field (2001 aminoacid dihedrals)
> 16: [DEPRECATED] Encad all-atom force field, using full solvent charges
> 17: [DEPRECATED] Encad all-atom force field, using scaled-down vacuum
> charges
> 18: [DEPRECATED] Gromacs force field (see manual)
> 19: [DEPRECATED] Gromacs force field with hydrogens for NMR
> 15
>
> Using the Oplsaa force field in directory oplsaa.ff
>
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/oplsaa.ff/aminoacids.r2b
> Reading 1HFX.pdb...
> WARNING: all CONECT records are ignored
> Read 'ALPHA-LACTALBUMIN', 1069 atoms
> Analyzing pdb file
> Splitting chemical chains based on TER records or chain id changing.
> WARNING: Chain identifier 'A' is used in two non-sequential blocks.
> They will be treated as separate chains unless you reorder your file.
> There are 2 chains and 1 blocks of water and 197 residues with 1069 atoms
>
>    chain  #res #atoms
>    1 'A'   123    995
>    2 'A'     1      1
>    3 ' '    73     73  (only water)
>
> All occupancies are one
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/oplsaa.ff/atomtypes.atp
> Atomtype 1
> Reading residue database... (oplsaa)
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/oplsaa.ff/aminoacids.rtp
> Residue 54
> Sorting it all out...
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/oplsaa.ff/aminoacids.hdb
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/oplsaa.ff/aminoacids.n.tdb
> Opening force field file
> /usr/local/gromacs/share/gromacs/top/oplsaa.ff/aminoacids.c.tdb
>
> Back Off! I just backed up topol.top to ./#topol.top.2#
> Processing chain 1 'A' (995 atoms, 123 residues)
> Analysing hydrogen-bonding network for automated assignment of histidine
>   protonation. 180 donors and 196 acceptors were found.
> There are 262 hydrogen bonds
> Will use HISE for residue 10
> Will use HISD for residue 32
> Will use HISE for residue 47
> Will use HISE for residue 107
> Identified residue LYS1 as a starting terminus.
> Identified residue GLN123 as a ending terminus.
> 8 out of 8 lines of specbond.dat converted successfully
> Special Atom Distance matrix:
>                      CYS6   HIS10   CYS28   HIS32   HIS47   CYS61   CYS73
>                      SG48   NE277   SG225  NE2262  NE2377   SG497   SG587
>     HIS10   NE277   0.715
>     CYS28   SG225   1.522   1.948
>     HIS32  NE2262   1.791   2.287   0.484
>     HIS47  NE2377   3.051   3.232   2.060   1.880
>     CYS61   SG497   2.817   2.797   2.313   2.287   1.017
>     CYS73   SG587   2.748   2.608   2.233   2.350   1.390   0.757
>     CYS77   SG615   2.932   2.917   2.465   2.415   1.078   0.203   0.934
>     MET90   SD718   2.683   2.405   2.447   2.639   1.913   1.131   0.544
>     CYS91   SG725   2.575   2.458   2.088   2.198   1.330   0.672   0.201
>    HIS107  NE2860   3.163   3.372   1.773   1.726   1.369   2.067   1.912
>    CYS111   SG890   1.677   2.062   0.202   0.475   1.889   2.183   2.098
>    CYS120   SG971   0.203   0.608   1.553   1.867   3.125   2.877   2.754
>                     CYS77   MET90   CYS91  HIS107  CYS111
>                     SG615   SD718   SG725  NE2860   SG890
>     MET90   SD718   1.271
>     CYS91   SG725   0.860   0.592
>    HIS107  NE2860   2.219   2.366   1.903
>    CYS111   SG890   2.339   2.344   1.960   1.576
>    CYS120   SG971   3.001   2.665   2.589   3.175   1.707
> Linking CYS-6 SG-48 and CYS-120 SG-971...
> Linking CYS-28 SG-225 and CYS-111 SG-890...
> Linking CYS-61 SG-497 and CYS-77 SG-615...
> Linking CYS-73 SG-587 and CYS-91 SG-725...
> Start terminus LYS-1: NH3+
> End terminus GLN-123: COO-
> Checking for duplicate atoms....
> Generating any missing hydrogen atoms and/or adding termini.
> Now there are 123 residues with 1955 atoms
> Chain time...
>
> Back Off! I just backed up topol_Protein_chain_A.itp to
> ./#topol_Protein_chain_A.itp.2#
> Making bonds...
> Number of bonds was 1978, now 1978
> Generating angles, dihedrals and pairs...
> Before cleaning: 5220 pairs
> Before cleaning: 5265 dihedrals
> Keeping all generated dihedrals
> Making cmap torsions...There are 5265 dihedrals,  380 impropers, 3584 angles
>            5187 pairs,     1978 bonds and     0 virtual sites
> Total mass 14206.088 a.m.u.
> Total charge -9.000 e
> Writing topology
>
> Back Off! I just backed up posre_Protein_chain_A.itp to
> ./#posre_Protein_chain_A.itp.2#
> Processing chain 2 'A' (1 atoms, 1 residues)
> Warning: Starting residue CA124 in chain not identified as Protein/RNA/DNA.
> Problem with chain definition, or missing terminal residues.
> This chain does not appear to contain a recognized chain molecule.
> If this is incorrect, you can edit residuetypes.dat to modify the behavior.
> 8 out of 8 lines of specbond.dat converted successfully
> Checking for duplicate atoms....
> Generating any missing hydrogen atoms and/or adding termini.
> Now there are 1 residues with 1 atoms
> Chain time...
>
> Back Off! I just backed up topol_Ion_chain_A2.itp to
> ./#topol_Ion_chain_A2.itp.2#
> Making bonds...
> No bonds
> Generating angles, dihedrals and pairs...
> Making cmap torsions...There are    0 dihedrals,    0 impropers,    0 angles
>               0 pairs,        0 bonds and     0 virtual sites
> Total mass 40.080 a.m.u.
> Total charge 2.000 e
> Writing topology
>
> Back Off! I just backed up posre_Ion_chain_A2.itp to
> ./#posre_Ion_chain_A2.itp.2#
> Processing chain 3 (73 atoms, 73 residues)
> Problem with chain definition, or missing terminal residues.
> This chain does not appear to contain a recognized chain molecule.
> If this is incorrect, you can edit residuetypes.dat to modify the behavior.
> 8 out of 8 lines of specbond.dat converted successfully
> Checking for duplicate atoms....
> Generating any missing hydrogen atoms and/or adding termini.
> Now there are 73 residues with 219 atoms
> Making bonds...
> Number of bonds was 146, now 146
> Generating angles, dihedrals and pairs...
> Making cmap torsions...There are    0 dihedrals,    0 impropers,   73 angles
>               0 pairs,      146 bonds and     0 virtual sites
> Total mass 1315.124 a.m.u.
> Total charge 0.000 e
> Including chain 1 in system: 1955 atoms 123 residues
> Including chain 2 in system: 1 atoms 1 residues
> Including chain 3 in system: 219 atoms 73 residues
> Now there are 2175 atoms and 197 residues
> Total mass in system 15561.292 a.m.u.
> Total charge in system -7.000 e
>
> Writing coordinate file...
>
> Back Off! I just backed up 1HFX_processed.gro to ./#1HFX_processed.gro.2#
>          --------- PLEASE NOTE ------------
> You have successfully generated a topology from: 1HFX.pdb.
> The Oplsaa force field and the spce water model are used.
>          --------- ETON ESAELP ------------
>
> Cheers
> James
>

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

Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 629
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441
http://mackerell.umaryland.edu/~jalemkul

==================================================


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