[gmx-users] add new residue and new atom

Malihe Hasanzadeh ml.hasanzadeh at gmail.com
Fri Jan 29 18:49:08 CET 2016


Dear Justin,
I know these Force fields as much as I can use them. I use always
AMBER99sb-ILDN in my simulations actually like this time, but I'm sorry for
notify name of force field as incomplete. I copied parameters of Lys
residue from .rtp file in AMBER99sb-ILDN for my new residue (KCX) and only
data of carbamyl group added to it (below) as I said before.
CX   OQ1
CX   OQ2
CX    HX
Malihe

On Fri, Jan 29, 2016 at 8:54 PM, Justin Lemkul <jalemkul at vt.edu> wrote:

>
>
> On 1/29/16 12:22 PM, Malihe Hasanzadeh wrote:
>
>> Dear Justin,
>> Is there any way to get parameters of KCX residue for amber99sb-ildn?
>>
>
> Well, how did you get the ones you have?  And are you familiar with what
> the differences are between AMBER99sb and AMBER99sb-ILDN?
>
> -Justin
>
> Thanks
>> Malihe
>>
>> On Fri, Jan 29, 2016 at 8:45 PM, Justin Lemkul <jalemkul at vt.edu> wrote:
>>
>>
>>>
>>> On 1/29/16 12:13 PM, Malihe Hasanzadeh wrote:
>>>
>>> Dear justin,
>>>> I forgot to write this step here, but I did this step also. I added (KCX
>>>> Protein) in .dat file. But unfortunately as you say the gromacs dosen't
>>>> identify my new residue!
>>>>
>>>>
>>> If this were true, pdb2gmx would not tell you otherwise.  You didn't do
>>> what you thought you did, or you modified the wrong files.
>>>
>>> What should I do? Is my added parameters for KCX residue correct?
>>>
>>>>
>>>>
>>> Follow the steps exactly in the link I provided.  That's all there is to
>>> it.
>>>
>>> -Justin
>>>
>>> Thanks
>>>
>>>> Malihe
>>>>
>>>> On Fri, Jan 29, 2016 at 8:26 PM, Justin Lemkul <jalemkul at vt.edu> wrote:
>>>>
>>>>
>>>>
>>>>> On 1/29/16 11:52 AM, Malihe Hasanzadeh wrote:
>>>>>
>>>>> Hi
>>>>>
>>>>>>
>>>>>> I used a PDB structure for MD simulation which it has a carbamylated
>>>>>> Lys
>>>>>> (KCX 220). This residue via carbamyl group bonded to metal in active
>>>>>> site.
>>>>>> So I had to define new residue(KCX), I copied parameters of Lys
>>>>>> residue
>>>>>> and
>>>>>> added carbamyl group and added to .rtp file in amber force field
>>>>>> (99sb)(gromacs5.0.4). I bring KCX parameters in below:
>>>>>>       [ KCX ]
>>>>>>     [ atoms ]
>>>>>>         N    N           -0.34790     1
>>>>>>         H    H            0.27470     2
>>>>>>        CA    CT          -0.24000     3
>>>>>>        HA    H1           0.14260     4
>>>>>>        CB    CT          -0.00940     5
>>>>>>       HB1    HC           0.03620     6
>>>>>>       HB2    HC           0.03620     7
>>>>>>        CG    CT           0.01870     8
>>>>>>       HG1    HC           0.01030     9
>>>>>>       HG2    HC           0.01030    10
>>>>>>        CD    CT          -0.04790    11
>>>>>>       HD1    HC           0.06210    12
>>>>>>       HD2    HC           0.06210    13
>>>>>>        CE    CT          -0.01430    14
>>>>>>       HE1    HP           0.11350    15
>>>>>>       HE2    HP           0.11350    16
>>>>>>        NZ    N3          -0.38540    17
>>>>>>       HZ1    H            0.34000    18
>>>>>>       HZ2    H            0.34000    19
>>>>>>       HZ3    H            0.34000    20
>>>>>>         C    C            0.73410    21
>>>>>>         O    O           -0.58940    22
>>>>>>        CX    C            0.73410    23
>>>>>>        HX    H            0.27470    24
>>>>>>       OQ1    O           -0.58940    25
>>>>>>       OQ2    O           -0.58940    26
>>>>>>     [ bonds ]
>>>>>>         N     H
>>>>>>         N    CA
>>>>>>        CA    HA
>>>>>>        CA    CB
>>>>>>        CA     C
>>>>>>        CB   HB1
>>>>>>        CB   HB2
>>>>>>        CB    CG
>>>>>>        CG   HG1
>>>>>>        CG   HG2
>>>>>>        CG    CD
>>>>>>        CD   HD1
>>>>>>        CD   HD2
>>>>>>        CD    CE
>>>>>>        CE   HE1
>>>>>>        CE   HE2
>>>>>>        CE    NZ
>>>>>>        NZ   HZ1
>>>>>>        NZ   HZ2
>>>>>>        NZ   HZ3
>>>>>>        NZ    CX
>>>>>>         C     O
>>>>>>        -C     N
>>>>>>        CX   OQ1
>>>>>>        CX   OQ2
>>>>>>        CX    HX
>>>>>>     [ impropers ]
>>>>>>        -C    CA     N     H
>>>>>>        CA    +N     C     O
>>>>>>        NZ   OQ1    CX   OQ2
>>>>>>
>>>>>> In addition this protein has two Ni ion, that I added its parameters
>>>>>> in
>>>>>> .atp .itp and .dat files.
>>>>>> Also my ligand has a F ion that when I docked with the protein, it
>>>>>> closed
>>>>>> to Ni ion in active site (distance 2.9 A). when I start MD simulation
>>>>>> I
>>>>>> faced with two problems:
>>>>>>
>>>>>> 1. when I run pdb2gmx gives many warning:
>>>>>>
>>>>>> Identified residue MET1 as a starting terminus.
>>>>>> Warning: Residue KCX220 in chain has different type (Other) from
>>>>>> starting
>>>>>> residue MET1 (Protein).
>>>>>> Warning: Residue ILE221 in chain has different type (Protein) from
>>>>>> starting
>>>>>> residue MET1 (Protein).
>>>>>> Warning: Residue HIS222 in chain has different type (Protein) from
>>>>>> starting
>>>>>> residue MET1 (Protein).
>>>>>> Warning: Residue GLU223 in chain has different type (Protein) from
>>>>>> starting
>>>>>> residue MET1 (Protein).
>>>>>> Warning: Residue ASP224 in chain has different type (Protein) from
>>>>>> starting
>>>>>> residue MET1 (Protein).
>>>>>> More than 5 unidentified residues at end of chain - disabling further
>>>>>> warnings.
>>>>>> Identified residue LEU219 as a ending terminus.
>>>>>>
>>>>>> My protein has 570 residue, but as you see the gromacs identified
>>>>>> residue
>>>>>> LEU219 as a ending terminus.!
>>>>>>
>>>>>> 2. when I used -missing option and continued my simulations, after
>>>>>> energy
>>>>>> minimization, I extract em.pdb file and I saw the distance between NI
>>>>>> ion
>>>>>> in active site with F ion in ligand is much more ( ~5 A) than before
>>>>>> in
>>>>>> complex.pdb. This means my ligand isn't stable in active site and it
>>>>>> is
>>>>>> moving away!
>>>>>>
>>>>>> please help me. what is my mistake?why ligand moving away and why
>>>>>> gromacs
>>>>>> doesn't identify end of the protein? Is there a relationship between
>>>>>> added
>>>>>> parameters and getting away of ligand?
>>>>>>
>>>>>>
>>>>>> You forgot step 5:
>>>>>>
>>>>>
>>>>>
>>>>> http://www.gromacs.org/Documentation/How-tos/Adding_a_Residue_to_a_Force_Field
>>>>>
>>>>> pdb2gmx writes your custom residue as its own chain, not bonded to the
>>>>> rest of the protein, so it is its own separate molecule.
>>>>>
>>>>> -Justin
>>>>>
>>>>> --
>>>>> ==================================================
>>>>>
>>>>> 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
>>>>>
>>>>> ==================================================
>>>>> --
>>>>> Gromacs Users mailing list
>>>>>
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>>>>> 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 629
>>> 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 629
> 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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