[gmx-users] PRODRG - .itp file

Luciane Vieira de Mello mello at cenargen.embrapa.br
Tue Dec 17 19:32:39 CET 2002


Dear all,

I 've been using the excellent PRODRG server with success recently, but
I'm having some unexpected problems this time.

My ligand is 2-phosphoglycerate.  The only change I made to the
PRODRG-derived parameters (the .itp file) was to make the three chemically
equivalent atoms the same in terms of charge etc. The problem is that
after energy minimization with these parameters, the phosphate group
becomes distorted.  The distortion is quite marked - see attached snapshot
and pdb file.  I've tried various things but I always get the distortion.
The only thing in the itp file which looks strange is the double entry for
one of the dihedrals

   6   5   2   1   1   0.0    1.0 3   0.0    1.0 3 ; DI     C2  O1P    P
O4P
   6   5   2   1   1   0.0    3.1 2   0.0    3.1 2 ; DI     C2  O1P    P
O4P

However, when I delete either one the distorion is much worse!


Can anybody help?

Thanks in advance



+-------------------------------------------------------------------------+
|                  Dra. Luciane Vieira de Mello Rigden                    |
| e-mail: mello at cenargen.embrapa.br                                       |
| Embrapa Recursos Geneticos e Biotecnologia                              |
| Parque Estacao Biologica           |  http://www.cenargen.embrapa.br    |
| PqEB - Final - Av. W3 Norte        |  Phone:  +55 (61)448-4741          |
| 70770-900, Brasilia-D.F.-BRAZIL    |  Fax:    +55 (61)340-3658          |
+-------------------------------------------------------------------------+



-------------- next part --------------
ATOM      1  O4P DRG     1      15.220  11.270  11.000  1.00  0.00
ATOM      2  P   DRG     1      13.650  10.900  11.140  1.00  0.00
ATOM      3  O2P DRG     1      13.760   9.440  11.240  1.00  0.00
ATOM      4  O3P DRG     1      13.140  11.530   9.910  1.00  0.00
ATOM      5  O1P DRG     1      13.090  11.510  12.510  1.00  0.00
ATOM      6  C2  DRG     1      12.250  12.690  12.560  1.00  0.00
ATOM      7  C1  DRG     1      11.340  12.860  13.840  1.00  0.00
ATOM      8  O2  DRG     1      10.520  13.850  13.800  1.00  0.00
ATOM      9  O1  DRG     1      11.410  12.130  14.820  1.00  0.00
ATOM     10  C3  DRG     1      13.130  13.940  12.450  1.00  0.00
ATOM     11  O3  DRG     1      12.280  15.090  12.380  1.00  0.00
ATOM     12  HAA DRG     1      11.470  14.700  12.900  1.00  0.00
-------------- next part --------------
 [ moleculetype ]
 ;name nrexcl
2PG      3
;       
 [ atoms ]
 ;  nr  type resnr resid  atom  cgnr charge
     1    OA     1 DRG     O4P     1   -1.087
     2     P     1 DRG       P     1    1.980
     3    OM     1 DRG     O2P     1   -1.087
     4    OM     1 DRG     O3P     1   -1.087
     5    OS     1 DRG     O1P     1   -0.720
     6   CH1     1 DRG      C2     2    0.000
     7     C     1 DRG      C1     3    0.270
     8    OM     1 DRG      O2     3   -0.635
     9    OM     1 DRG      O1     3   -0.635
    10   CH2     1 DRG      C3     4    0.150
    11    OA     1 DRG      O3     4   -0.548
    12    HO     1 DRG     HAA     4    0.398
 [ bonds ]
 ;ai  aj  fu    c0          c1
   1   2   1 0.161    251040.0 0.161    251040.0 ;   O4P    P
   2   3   1 0.148    376560.0 0.148    376560.0 ;     P  O2P
   2   4   1 0.148    376560.0 0.148    376560.0 ;     P  O3P
   2   5   1 0.161    251040.0 0.161    251040.0 ;     P  O1P
   5   6   1 0.143    334720.0 0.143    334720.0 ;   O1P   C2
   6   7   1 0.153    334720.0 0.153    334720.0 ;    C2   C1
   6  10   1 0.153    334720.0 0.153    334720.0 ;    C2   C3
   7   8   1 0.125    418400.0 0.125    418400.0 ;    C1   O2
   7   9   1 0.125    418400.0 0.125    418400.0 ;    C1   O1
  10  11   1 0.143    334720.0 0.143    334720.0 ;    C3   O3
  11  12   1 0.100    313800.0 0.100    313800.0 ;    O3  HAA
 [ pairs ]
 ;ai  aj  fu    c0          c1
   1   6   1		       ;   O4P    C2
   2   7   1		       ;     P  C1
   2  10   1		       ;     P  C3
   3   6   1		       ;     O2P  C2
   4   6   1		       ;     O3P  O1P
   5   8   1		       ;   O1P   C2
   5   9   1		       ;   O1P   C2
   5  11   1		       ;   O1P   C2
   6  12   1		       ;    C2   C1
   7  11   1		       ;    C2   C3
   8  10   1		       ;    C1   O2
   9  10   1		       ;    C1   O1
 [ angles ]
 ;ai  aj  ak  fu    c0          c1
   1   2   3   1 109.6       397.5 109.6       397.5 ;   O4P    P  O2P
   1   2   4   1 109.6       397.5 109.6       397.5 ;   O4P    P  O3P
   3   2   4   1 109.6       397.5 109.6       397.5 ;   O2P    P  O3P
   1   2   5   1 109.6       397.5 109.6       397.5 ;   O4P    P  O1P
   3   2   5   1 109.6       397.5 109.6       397.5 ;   O2P    P  O1P
   4   2   5   1 109.6       397.5 109.6       397.5 ;   O3P    P  O1P
   2   5   6   1 120.0       397.5 120.0       397.5 ;     P  O1P   C2
   5   6   7   1 109.5       460.2 109.5       460.2 ;   O1P   C2   C1
   5   6  10   1 109.5       460.2 109.5       460.2 ;   O1P   C2   C3
   7   6  10   1 109.5       460.2 109.5       460.2 ;    C1   C2   C3
   6   7   8   1 117.0       502.1 117.0       502.1 ;    C2   C1   O2
   6   7   9   1 117.0       502.1 117.0       502.1 ;    C2   C1   O1
   8   7   9   1 126.0       502.1 126.0       502.1 ;    O2   C1   O1
   6  10  11   1 109.5       460.2 109.5       460.2 ;    C2   C3   O3
  10  11  12   1 109.5       397.5 109.5       397.5 ;    C3   O3  HAA
 [ dihedrals ]
 ;ai  aj  ak  al  fu    c0    c1 m  c0   c1 m
   7   6   9   8   2   0.0 1673.6 0   0.0 1673.6 0 ; IDI    C1   C2   O1   O2
   2   1   3   4   2  35.3  836.8 0  35.3  836.8 0 ; IDI     P  O4P  O2P  O3P
   6   5  10   7   2  35.3  836.8 0  35.3  836.8 0 ; IDI    C2  O1P   C3   C1
   6   5   2   1   1   0.0    1.0 3   0.0    1.0 3 ; DI     C2  O1P    P  O4P
;   6   5   2   1   1   0.0    3.1 2   0.0    3.1 2 ; DI     C2  O1P    P  O4P
   2   5   6  10   1   0.0    1.3 3   0.0    1.3 3 ; DI      P  O1P   C2   C3
   5   6   7   9   1   0.0    0.4 6   0.0    0.4 6 ; DI    O1P   C2   C1   O1
  11  10   6   5   1   0.0    5.9 3   0.0    5.9 3 ; DI     O3   C3   C2  O1P
   6  10  11  12   1   0.0    1.3 3   0.0    1.3 3 ; DI     C2   C3   O3  HAA



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