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

Ahmet yıldırım ahmedo047 at gmail.com
Fri Apr 4 15:25:35 CEST 2014


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

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
[ 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
>>>
>>> * Please search the archive at http://www.gromacs.org/
>>> Support/Mailing_Lists/GMX-Users_List before posting!
>>>
>>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>>
>>> * For (un)subscribe requests visit
>>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>>> send a mail to gmx-users-request at gromacs.org.
>>>
>>>
>>
>>
>>
> --
> ==================================================
>
> 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!
>
> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>
> * For (un)subscribe requests visit
> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
> send a mail to gmx-users-request at gromacs.org.
>



-- 
Ahmet Yıldırım


More information about the gromacs.org_gmx-users mailing list