[gmx-users] adding metal-bonding parameters to a force field

Justin Lemkul jalemkul at vt.edu
Fri Apr 4 15:31:03 CEST 2014



On 4/4/14, 9:25 AM, Ahmet yıldırım wrote:
> Dear Justin,
>
> Firstly, I renamed HETATM 2068  O  HOH A1001 in pdb. This water is bound to
> Zn.
> its new name:
> HETATM 2068  OZ  OWZ A1001
>
> Zn is bound to three Histidine atoms (two NE2 atoms and one ND1 atom) and a
> water molecule in carbonic anhydrase as I said before. I did the following
> changes on amber99sb-ildn. What do you suggestion?
>
> specbond.dat:
> 11
> ..
> HIS     ND1     1       ZN      Zn      1       0.205   HIDZ    ZNW
> ;modified
> HIS     NE2     1       ZN      Zn      1       0.205   HIEZ    ZNW
> ;modified
> OWZ     OZ      1       ZN      Zn      1       0.23    ZOH2    ZNW
> ;modified
>

Are these bonds correctly generated?  The previous topology output suggests not, 
because ZN is not renamed to ZNW.

> residuetypes.dat:
> ZNW    Ion   ;modified
> ZOH2    water ;modified
> OWZ    water ;modified
> HIDZ    Protein
> HIEZ    Protein
>
> aminoacids.hdb:
> OWZ    1 ;modified
> 2    7    HZ    OZ
> ..
> HIDZ    6
> 1    1    H    N    -C    CA
> 1    5    HA    CA    N    CB    C
> 2    6    HB    CB    CA    CG
> 1    1    HD1    ND1    CG    CE1
> 1    1    HE1    CE1    ND1    NE2
> 1    1    HD2    CD2    CG    NE2
> HIEZ    6
> 1    1    H    N    -C    CA
> 1    5    HA    CA    N    CB    C
> 2    6    HB    CB    CA    CG
> 1    1    HE1    CE1    ND1    NE2
> 1    1    HE2    NE2    CE1    CD2
> 1    1    HD2    CD2    CG    NE2
>
> aminoacids.rtp:
> [ ZNW ];modified
>   [ atoms ]
>     ZN     Zn           0.89230     1
>
> [ ZOH2 ];modified
>   [ atoms ]
>      OZ   OZ           -0.8824    0
>     HZ1   HZ            0.5001    0
>     HZ2   HZ            0.5001    0
>   [ bonds ]
>      OZ   HZ1
>      OZ   HZ2
>
> [ OWZ ];modified
>   [ atoms ]
>      OZ   OZ           -0.8824    0
>     HZ1   HZ            0.5001    0
>     HZ2   HZ            0.5001    0
>   [ bonds ]
>      OZ   HZ1
>      OZ   HZ2
> [ HIDZ ];modified
>   [ atoms ]
>       N    N           -0.41570     1
>       H    H            0.27190     2
>      CA    CT           0.01880     3
>      HA    H1           0.08810     4
>      CB    CT          -0.04620     5
>     HB1    HC           0.04020     6
>     HB2    HC           0.04020     7
>      CG    CC          -0.02660     8
>     ND1    NA          -0.38110     9
>     HD1    H            0.36490    10
>     CE1    CR           0.20570    11
>     HE1    H5           0.13920    12
>     NE2    NB          -0.57270    13
>     CD2    CV           0.12920    14
>     HD2    H4           0.11470    15
>       C    C            0.59730    16
>       O    O           -0.56790    17
>   [ bonds ]
>       N     H
>       N    CA
>      CA    HA
>      CA    CB
>      CA     C
>      CB   HB1
>      CB   HB2
>      CB    CG
>      CG   ND1
>      CG   CD2
>     ND1   HD1
>     ND1   CE1
>     CE1   HE1
>     CE1   NE2
>     NE2   CD2
>     CD2   HD2
>       C     O
>      -C     N
>   [ impropers ]
>      -C    CA     N     H
>      CA    +N     C     O
>      CG   CE1   ND1   HD1
>      CG   NE2   CD2   HD2
>     ND1   NE2   CE1   HE1
>     ND1   CD2    CG    CB
>
> [ HIEZ ];modified
>   [ atoms ]
>       N    N           -0.41570     1
>       H    H            0.27190     2
>      CA    CT          -0.05810     3
>      HA    H1           0.13600     4
>      CB    CT          -0.00740     5
>     HB1    HC           0.03670     6
>     HB2    HC           0.03670     7
>      CG    CC           0.18680     8
>     ND1    NB          -0.54320     9
>     CE1    CR           0.16350    10
>     HE1    H5           0.14350    11
>     NE2    NA          -0.27950    12
>     HE2    H            0.33390    13
>     CD2    CW          -0.22070    14
>     HD2    H4           0.18620    15
>       C    C            0.59730    16
>       O    O           -0.56790    17
>   [ bonds ]
>       N     H
>       N    CA
>      CA    HA
>      CA    CB
>      CA     C
>      CB   HB2
>      CB   HB1
>      CB    CG
>      CG   ND1
>      CG   CD2
>     ND1   CE1
>     CE1   HE1
>     CE1   NE2
>     NE2   HE2
>     NE2   CD2
>     CD2   HD2
>       C     O
>      -C     N
>   [ impropers ]
>      -C    CA     N     H
>      CA    +N     C     O
>     CE1   CD2   NE2   HE2
>      CG   NE2   CD2   HD2
>     ND1   NE2   CE1   HE1
>     ND1   CD2    CG    CB
>
> atomtypes.atp:
> OZ                16.00000    ; modified
> HZ                 1.00800    ; modified
>
> ffbonded.itp:
> [ bondtypes ]
>    Zn NA         1    0.20500   16744.0 ;modified
>    Zn NB         1    0.20500   16744.0 ;modified
>    Zn OZ         1    0.23000   16744.0 ;modified

You get the fatal error about missing bond types because you haven't defined the 
OZ-HZ bond here.

-Justin

> [ angletypes ]
> HW  OW  HW           1   104.5      142.490 ; TIP3P water ;modified
>
> CR  NA  Zn           1   126.0       83.720 ;modified
> CW  NB  Zn           1   126.0       83.720 ;modified
> NA  Zn  NB           1   109.5       96.278 ;modified
> NB  Zn  NB           1   109.5       96.278 ;modified
> NA  Zn  OZ           1   109.5       96.278 ;modified
> NB  Zn  OZ           1   109.5       96.278 ;modified
> Zn  OZ  HZ           1   124.0       83.720 ;modified
> HZ  OZ  HZ           1   104.5     4186.000 ;modified
>
> [ dihedraltypes ]
>   X   Zn  NA  X     9       0.0      0.00000     3  ;modified
>   X   Zn  NB  X     9       0.0      0.00000     3  ;modified
>   X   Zn  OZ  X     9       0.0      0.00000     3  ;modified
>
> ffnonbonded.itp:
> OW           8      16.00    0.0000  A   1.76820e-01  6.371092e-01
> ;modified
> OZ           8      16.00    0.0000  A   3.15061e-01  6.36386e-01
> ;modified
> HZ           1       1.008   0.0000  A   0.00000e+00  0.00000e+00
> ;modified
> Zn          30      65.4     0.0000  A   1.10000e-01  5.23250e-02 ;modified
>
>
> 2014-04-04 15:51 GMT+03:00 Justin Lemkul <jalemkul at vt.edu>:
>
>>
>>
>> On 4/4/14, 8:47 AM, Ahmet yıldırım wrote:
>>
>>> Hi,
>>>
>>> The bond types are set properly in ffbonded.itp. But I get the following
>>> errors after grompp command. How can I fix it?
>>> ERROR 1 [file protein_Ion_chain_A2.itp, line 33]:
>>>     No default Bond types
>>>
>>>
>>> ERROR 2 [file protein_Ion_chain_A2.itp, line 34]:
>>>     No default Bond types
>>>
>>> protein_Ion_chain_A2.itp:
>>> [ moleculetype ]
>>> ; Name            nrexcl
>>> Ion_chain_A2        3
>>>
>>> [ atoms ]
>>> ;   nr       type  resnr residue  atom   cgnr     charge       mass
>>> typeB    chargeB      massB
>>> ; residue 262 ZN  rtp ZN   q +2.0
>>>        1         Zn    262     ZN     ZN      1          2       65.4   ;
>>> qtot 2
>>>
>>
>> If I'm remembering your model right, the Zn-HOH complex doesn't bear a +2
>> charge on Zn.  Is this what you actually want?
>>
>>
>>   ; residue 1001 OWZ rtp OWZ  q +0.1
>>>        2         OZ   1001    OWZ     OZ      2    -0.8824         16   ;
>>> qtot 1.118
>>>        3         HZ   1001    OWZ    HZ1      2     0.5001      1.008   ;
>>> qtot 1.618
>>>        4         HZ   1001    OWZ    HZ2      2     0.5001      1.008   ;
>>> qtot 2.118
>>>
>>> [ bonds ]
>>> ;  ai    aj funct            c0            c1            c2            c3
>>>       2     3     1
>>>       2     4     1
>>>
>>>
>> Apparently whatever ffbonded.itp file that is being read doesn't have
>> these parameters.  Unfortunately, there's not enough information to say
>> why.  If OZ-HZ parameters were there, there would be no reason they
>> wouldn't be read.
>>
>> -Justin
>>
>>
>>   [ angles ]
>>> ;  ai    aj    ak funct            c0            c1
>>> c2            c3
>>>       3     2     4     1
>>>
>>> ; Include Position restraint file
>>> #ifdef POSRES
>>> #include "posre_Ion_chain_A2.itp"
>>> #endif
>>>
>>>
>>>
>>>
>>>
>>> 2014-04-04 0:32 GMT+03:00 Justin Lemkul <jalemkul at vt.edu>:
>>>
>>>
>>>>
>>>> On 4/3/14, 2:58 PM, Gmail2 wrote:
>>>>
>>>>   Dear Justin,
>>>>>
>>>>> Zn bound to three Histidine atoms and a water in carbonic anhydrase.
>>>>> This
>>>>> water bound to Zn has different parameters than solvent water. That
>>>>> parameters is present in literature. How should I set up such a system?
>>>>>
>>>>> PS: I will use 'pdb2gmx' with -vsite hydrogens.
>>>>>
>>>>>
>>>>>   If you need virtual sites, then you need to figure out how to properly
>>>> build a virtual site database entry for that particular type of molecule.
>>>>    That's entirely separate from any of the force field parameters you've
>>>> shown before, but realize that doing so negates most of the Zn-HOH bonded
>>>> parameters you posted.
>>>>
>>>> -Justin
>>>>
>>>>
>>>> --
>>>> ==================================================
>>>>
>>>> Justin A. Lemkul, Ph.D.
>>>> Ruth L. Kirschstein NRSA Postdoctoral Fellow
>>>>
>>>> Department of Pharmaceutical Sciences
>>>> School of Pharmacy
>>>> Health Sciences Facility II, Room 601
>>>> University of Maryland, Baltimore
>>>> 20 Penn St.
>>>> Baltimore, MD 21201
>>>>
>>>> jalemkul at outerbanks.umaryland.edu | (410) 706-7441
>>>> http://mackerell.umaryland.edu/~jalemkul
>>>>
>>>> ==================================================
>>>> --
>>>> Gromacs Users mailing list
>>>>
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>>>>
>>>
>>>
>>>
>> --
>> ==================================================
>>
>> Justin A. Lemkul, Ph.D.
>> Ruth L. Kirschstein NRSA Postdoctoral Fellow
>>
>> Department of Pharmaceutical Sciences
>> School of Pharmacy
>> Health Sciences Facility II, Room 601
>> University of Maryland, Baltimore
>> 20 Penn St.
>> Baltimore, MD 21201
>>
>> jalemkul at outerbanks.umaryland.edu | (410) 706-7441
>> http://mackerell.umaryland.edu/~jalemkul
>>
>> ==================================================
>> --
>> Gromacs Users mailing list
>>
>> * Please search the archive at http://www.gromacs.org/
>> Support/Mailing_Lists/GMX-Users_List before posting!
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>
>
>

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

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

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 601
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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