[gmx-users] Topology file of molecule

Krzysztof Kolman krzysztof.kolman at gmail.com
Fri Nov 24 09:12:29 CET 2017


Dear Magnus and Justin,

Thank you very much for your help.

Kind regards,
Krzysztof

2017-11-23 13:55 GMT+01:00 Justin Lemkul <jalemkul at vt.edu>:

>
>
> On 11/23/17 7:51 AM, Magnus Lundborg wrote:
>
>> Dear Krzysztof,
>>
>> I wouldn't be too worried about the fact that GAFF parameters have been
>> used for proper and improper torsion angles. It happens quite a lot with
>> the OPLS-AA forcefield. But as always, it is good to verify that the
>> topology behaves as expected. Unfortunately there is no objective way to do
>> this. If there are no experimentally measured properties available of your
>> molecule it is a bit risky to proceed. However, I would recommend running
>> short simulations of the molecule in vacuum (NVT) and in a simulation box
>> solvated by itself just to see that it does at least not behave very
>> strangely. If it seems OK I think you can proceed with your studies, but as
>> always with an eye open for strange behaviour.
>>
>>
> The rigorous test is to perform a QM energy scan over the dihedral. Rotate
> in increments of 15 degrees, optimize, and calculate the energy. This gives
> you a one-dimensional potential energy surface. Do the corresponding MM
> evaluations with the force field (in vacuo) and verify that the positions
> and magnitudes of the minima are comparable. If they're not, you need to do
> some refinement of the parameters. Otherwise it is extremely hard to define
> what "strange" is in a simulation; you don't know what the molecule should
> be doing in the first place.
>
> -Justin
>
>
> I hope that helps you.
>>
>> Best regards,
>>
>> Magnus
>>
>> On 2017-11-23 10:24, Krzysztof Kolman wrote:
>>
>>> Dear Gromacs Users,
>>>
>>> I would like to perform a simulation of adsorption of
>>> 3,4-Dihydroxybenzoic
>>> acid (34DHBA) on silica surface using the OPLS-AA forcefield. I created
>>> topology files for the silica surface based on the information found in
>>> papers describing simulations of quartz (Wensink 2000
>>> - 10.1021/la053284f, van der Spoel 2006 -10.1021/la053284f ). The
>>> topology
>>> for 34DHBA was created using STaGE script (Lundborg 2015
>>> - 10.1021/jp505332p) but some of the parameters (dihedrals) were missing
>>> and GAFF parameters were used instead. Please find below the content of
>>> itp
>>> file:
>>>
>>> [ moleculetype ]
>>> ; Name            nrexcl
>>>   34DHBA_opls 3
>>>
>>> [ atoms ]
>>> ;   nr  type  resi  res  atom  cgnr     charge      mass       ; qtot
>>>   bond_type
>>>    1    opls_145 1   LIG   C1    1     -0.115000   12.01100 ; -0.115000
>>>   CA
>>>    2    opls_166 1   LIG   C2    2      0.150000   12.01100 ; 0.035000
>>>   CA
>>>    3    opls_166 1   LIG   C3    3      0.150000   12.01100 ; 0.185000
>>>   CA
>>>    4    opls_145 1   LIG   C4    4     -0.115000   12.01100 ; 0.070000
>>>   CA
>>>    5    opls_145 1   LIG   C5    5     -0.115000   12.01100 ; -0.045000
>>>   CA
>>>    6    opls_145 1   LIG   C6    6     -0.115000   12.01100 ; -0.160000
>>>   CA
>>>    7    opls_167 1   LIG   OC3   7     -0.585000   15.99940 ; -0.745000
>>>   OH
>>>    8    opls_167 1   LIG   OC2   8     -0.585000   15.99940 ; -1.330000
>>>   OH
>>>    9    opls_470 1   LIG   C9    9      0.635000   12.01100 ; -0.695000
>>>   C
>>>    10   opls_269 1   LIG   OC91  10    -0.440000   15.99940 ; -1.135000
>>>   O_3
>>>    11   opls_268 1   LIG   OC92  11    -0.530000   15.99940 ; -1.665000
>>>   OH
>>>    12   opls_146 1   LIG   HC1   12     0.115000    1.00800 ; -1.550000
>>>   HA
>>>    13   opls_146 1   LIG   HC4   13     0.115000    1.00800 ; -1.435000
>>>   HA
>>>    14   opls_146 1   LIG   HC6   14     0.115000    1.00800 ; -1.320000
>>>   HA
>>>    15   opls_168 1   LIG   HO3   15     0.435000    1.00800 ; -0.885000
>>>   HO
>>>    16   opls_168 1   LIG   HO2   16     0.435000    1.00800 ; -0.450000
>>>   HO
>>>    17   opls_270 1   LIG   HO92  17     0.450000    1.00800 ; 0.000000
>>>   HO
>>>
>>> [ bonds ]
>>> ;   ai     aj funct   r             k
>>>      1   2   1   1.4000e-01   3.9246e+05 ; CA - CA
>>>      1   6   1   1.4000e-01   3.9246e+05 ; CA - CA
>>>      1   12   1   1.0800e-01   3.0711e+05 ; CA - HA
>>>      2   3   1   1.4000e-01   3.9246e+05 ; CA - CA
>>>      2   8   1   1.3640e-01   3.7656e+05 ; CA - OH
>>>      3   4   1   1.4000e-01   3.9246e+05 ; CA - CA
>>>      3   7   1   1.3640e-01   3.7656e+05 ; CA - OH
>>>      4   5   1   1.4000e-01   3.9246e+05 ; CA - CA
>>>      4   13   1   1.0800e-01   3.0711e+05 ; CA - HA
>>>      5   6   1   1.4000e-01   3.9246e+05 ; CA - CA
>>>      5   9   1   1.4900e-01   3.3472e+05 ; CA - C
>>>      6   14   1   1.0800e-01   3.0711e+05 ; CA - HA
>>>      7   15   1   9.4500e-02   4.6275e+05 ; OH - HO
>>>      8   16   1   9.4500e-02   4.6275e+05 ; OH - HO
>>>      9   10   1   1.2290e-01   4.7698e+05 ; C - O_3
>>>      9   11   1   1.3640e-01   3.7656e+05 ; C - OH
>>>      11   17   1   9.4500e-02   4.6275e+05 ; OH - HO
>>>
>>> [ pairs ]
>>> ;   ai     aj    funct
>>>       1      4      1 ;     C1 - C4
>>>       1      7      1 ;     C1 - OC3
>>>       1      9      1 ;     C1 - C9
>>>       1     16      1 ;     C1 - HO2
>>>       2      5      1 ;     C2 - C5
>>>       2     13      1 ;     C2 - HC4
>>>       2     14      1 ;     C2 - HC6
>>>       2     15      1 ;     C2 - HO3
>>>       3      9      1 ;     C3 - C9
>>>       3     16      1 ;     C3 - HO2
>>>       4      8      1 ;     C4 - OC2
>>>       4     10      1 ;     C4 - OC91
>>>       4     11      1 ;     C4 - OC92
>>>       4     14      1 ;     C4 - HC6
>>>       4     15      1 ;     C4 - HO3
>>>       5      7      1 ;     C5 - OC3
>>>       5     17      1 ;     C5 - HO92
>>>       6      3      1 ;     C6 - C3
>>>       6      8      1 ;     C6 - OC2
>>>       6     10      1 ;     C6 - OC91
>>>       6     11      1 ;     C6 - OC92
>>>       6     13      1 ;     C6 - HC4
>>>       7      8      1 ;    OC3 - OC2
>>>       7     13      1 ;    OC3 - HC4
>>>       9     13      1 ;     C9 - HC4
>>>       9     14      1 ;     C9 - HC6
>>>      10     17      1 ;   OC91 - HO92
>>>      12      3      1 ;    HC1 - C3
>>>      12      5      1 ;    HC1 - C5
>>>      12      8      1 ;    HC1 - OC2
>>>      12     14      1 ;    HC1 - HC6
>>>
>>> [ angles ]
>>> ;   ai     aj     ak    funct   theta         cth
>>>      1   2   3   1   1.2000e+02   5.2718e+02 ; CA - CA - CA
>>>      1   2   8   1   1.2000e+02   5.8576e+02 ; CA - CA - OH
>>>      1   6   5   1   1.2000e+02   5.2718e+02 ; CA - CA - CA
>>>      1   6   14   1   1.2000e+02   2.9288e+02 ; CA - CA - HA
>>>      2   1   6   1   1.2000e+02   5.2718e+02 ; CA - CA - CA
>>>      2   1   12   1   1.2000e+02   2.9288e+02 ; CA - CA - HA
>>>      2   3   4   1   1.2000e+02   5.2718e+02 ; CA - CA - CA
>>>      2   3   7   1   1.2000e+02   5.8576e+02 ; CA - CA - OH
>>>      2   8   16   1   1.1300e+02   2.9288e+02 ; CA - OH - HO
>>>      3   2   8   1   1.2000e+02   5.8576e+02 ; CA - CA - OH
>>>      3   4   5   1   1.2000e+02   5.2718e+02 ; CA - CA - CA
>>>      3   4   13   1   1.2000e+02   2.9288e+02 ; CA - CA - HA
>>>      3   7   15   1   1.1300e+02   2.9288e+02 ; CA - OH - HO
>>>      4   3   7   1   1.2000e+02   5.8576e+02 ; CA - CA - OH
>>>      4   5   6   1   1.2000e+02   5.2718e+02 ; CA - CA - CA
>>>      4   5   9   1   1.2000e+02   7.1128e+02 ; CA - CA - C
>>>      5   4   13   1   1.2000e+02   2.9288e+02 ; CA - CA - HA
>>>      5   6   14   1   1.2000e+02   2.9288e+02 ; CA - CA - HA
>>>      5   9   10   1   1.2040e+02   6.6944e+02 ; CA - C - O_3
>>>      5   9   11   1   1.2000e+02   5.8576e+02 ; CA - C - OH
>>>      6   1   12   1   1.2000e+02   2.9288e+02 ; CA - CA - HA
>>>      6   5   9   1   1.2000e+02   7.1128e+02 ; CA - CA - C
>>>      9   11   17   1   1.1300e+02   2.9288e+02 ; C - OH - HO
>>>      10   9   11   1   1.2100e+02   6.6944e+02 ; O_3 - C - OH
>>>
>>> [ dihedrals ] ; propers
>>> ; for gromacs 4.5 or higher, using funct 9
>>> ;    i      j      k      l   func   phase     kd      pn
>>>       1      2      3      4      9   180.00  15.16700   2 ; C1-    C2-
>>>    C3-    C4  !Warning using GAFF parameters!
>>>       1      2      3      7      9   180.00  15.16700   2 ; C1-    C2-
>>>    C3-   OC3  !Warning using GAFF parameters!
>>>       1      2      8     16      9   180.00   3.76560   2 ; C1-    C2-
>>>   OC2-   HO2  !Warning using GAFF parameters!
>>>       1      6      5      4      9   180.00  15.16700   2 ; C1-    C6-
>>>    C5-    C4  !Warning using GAFF parameters!
>>>       1      6      5      9      9   180.00  15.16700   2 ; C1-    C6-
>>>    C5-    C9  !Warning using GAFF parameters!
>>>       2      1      6      5      9   180.00  15.16700   2 ; C2-    C1-
>>>    C6-    C5  !Warning using GAFF parameters!
>>>       2      1      6     14      9   180.00  15.16700   2 ; C2-    C1-
>>>    C6-   HC6  !Warning using GAFF parameters!
>>>       2      3      4      5      9   180.00  15.16700   2 ; C2-    C3-
>>>    C4-    C5  !Warning using GAFF parameters!
>>>       2      3      4     13      9   180.00  15.16700   2 ; C2-    C3-
>>>    C4-   HC4  !Warning using GAFF parameters!
>>>       2      3      7     15      9   180.00   3.76560   2 ; C2-    C3-
>>>   OC3-   HO3  !Warning using GAFF parameters!
>>>       3      2      8     16      9   180.00   3.76560   2 ; C3-    C2-
>>>   OC2-   HO2  !Warning using GAFF parameters!
>>>       3      4      5      6      9   180.00  15.16700   2 ; C3-    C4-
>>>    C5-    C6  !Warning using GAFF parameters!
>>>       3      4      5      9      9   180.00  15.16700   2 ; C3-    C4-
>>>    C5-    C9  !Warning using GAFF parameters!
>>>       4      3      2      8      9   180.00  15.16700   2 ; C4-    C3-
>>>    C2-   OC2  !Warning using GAFF parameters!
>>>       4      3      7     15      9   180.00   3.76560   2 ; C4-    C3-
>>>   OC3-   HO3  !Warning using GAFF parameters!
>>>       4      5      6     14      9   180.00  15.16700   2 ; C4-    C5-
>>>    C6-   HC6  !Warning using GAFF parameters!
>>>       4      5      9     10      9   180.00   4.18400   2 ; C4-    C5-
>>>    C9-  OC91  !Warning using GAFF parameters!
>>>       4      5      9     11      9   180.00   4.18400   2 ; C4-    C5-
>>>    C9-  OC92  !Warning using GAFF parameters!
>>>       5      4      3      7      9   180.00  15.16700   2 ; C5-    C4-
>>>    C3-   OC3  !Warning using GAFF parameters!
>>>       5      9     11     17      9   180.00   9.62320   2 ; C5-    C9-
>>> OC92-  HO92  !Warning using GAFF parameters!
>>>       6      1      2      3      9   180.00  15.16700   2 ; C6-    C1-
>>>    C2-    C3  !Warning using GAFF parameters!
>>>       6      1      2      8      9   180.00  15.16700   2 ; C6-    C1-
>>>    C2-   OC2  !Warning using GAFF parameters!
>>>       6      5      4     13      9   180.00  15.16700   2 ; C6-    C5-
>>>    C4-   HC4  !Warning using GAFF parameters!
>>>       6      5      9     10      9   180.00   4.18400   2 ; C6-    C5-
>>>    C9-  OC91  !Warning using GAFF parameters!
>>>       6      5      9     11      9   180.00   4.18400   2 ; C6-    C5-
>>>    C9-  OC92  !Warning using GAFF parameters!
>>>       7      3      2      8      9   180.00  15.16700   2 ; OC3-    C3-
>>>    C2-   OC2  !Warning using GAFF parameters!
>>>       7      3      4     13      9   180.00  15.16700   2 ; OC3-    C3-
>>>    C4-   HC4  !Warning using GAFF parameters!
>>>       9      5      4     13      9   180.00  15.16700   2 ; C9-    C5-
>>>    C4-   HC4  !Warning using GAFF parameters!
>>>       9      5      6     14      9   180.00  15.16700   2 ; C9-    C5-
>>>    C6-   HC6  !Warning using GAFF parameters!
>>>      10      9     11     17      9     0.00   7.94960   1 ; OC91-    C9-
>>> OC92-  HO92  !Warning using GAFF parameters!
>>>      10      9     11     17      9   180.00   9.62320   2 ; OC91-    C9-
>>> OC92-  HO92  !Warning using GAFF parameters!
>>>      12      1      2      3      9   180.00  15.16700   2 ; HC1-    C1-
>>>    C2-    C3  !Warning using GAFF parameters!
>>>      12      1      2      8      9   180.00  15.16700   2 ; HC1-    C1-
>>>    C2-   OC2  !Warning using GAFF parameters!
>>>      12      1      6      5      9   180.00  15.16700   2 ; HC1-    C1-
>>>    C6-    C5  !Warning using GAFF parameters!
>>>      12      1      6     14      9   180.00  15.16700   2 ; HC1-    C1-
>>>    C6-   HC6  !Warning using GAFF parameters!
>>>
>>> [ dihedrals ] ; impropers
>>> ; treated as propers in GROMACS to use correct AMBER analytical function
>>> ;    i      j      k      l   func   phase     kd      pn
>>>       1      3      2      8      4   180.00   4.60240   2 ; C1-    C3-
>>>    C2-   OC2  !Warning using GAFF parameters!
>>>       1      5      6     14      4   180.00   4.60240   2 ; C1-    C5-
>>>    C6-   HC6  !Warning using GAFF parameters!
>>>       2      4      3      7      4   180.00   4.60240   2 ; C2-    C4-
>>>    C3-   OC3  !Warning using GAFF parameters!
>>>       3      5      4     13      4   180.00   4.60240   2 ; C3-    C5-
>>>    C4-   HC4  !Warning using GAFF parameters!
>>>       5     10      9     11      4   180.00  43.93200   2 ; C5-  OC91-
>>>    C9-  OC92  !Warning using GAFF parameters!
>>>       9      4      5      6      4   180.00   4.60240   2 ; C9-    C4-
>>>    C5-    C6  !Warning using GAFF parameters!
>>>      12      1      6      2      4   180.00   4.60240   2 ; HC1-    C1-
>>>    C6-    C2  !Warning using GAFF parameters!
>>>
>>> Generally one should not mix different forcefiedls but my question is how
>>> big "mistake" I make running a simulation using the parameters shown
>>> above.
>>> Is there any benchmark that allows to evaluate the quality of a topology
>>> file (maybe by calculating some experimental properties)?
>>>
>>> Thank you in advance for your help.
>>>
>>> Best regards,
>>> Krzysztof
>>>
>>
>>
>>
> --
> ==================================================
>
> Justin A. Lemkul, Ph.D.
> Assistant Professor
> Virginia Tech Department of Biochemistry
>
> 303 Engel Hall
> 340 West Campus Dr.
> Blacksburg, VA 24061
>
> jalemkul at vt.edu | (540) 231-3129
> http://www.biochem.vt.edu/people/faculty/JustinLemkul.html
>
> ==================================================
>
>
> --
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