[gmx-users] Re: Adding chromophore parameters to the charmm force field

Justin A. Lemkul jalemkul at vt.edu
Wed Feb 23 12:54:16 CET 2011


http://www.gromacs.org/Documentation/How-tos/Adding_a_Residue_to_a_Force_Field

If you have specific implementation questions based on this information, post 
those.  Right now, your question is too broad for anyone to invest the 
significant amount of time it would take to walk you through the whole process.

-Justin

bharat gupta wrote:
> Hi,
> 
> I have obtained the chromophore parameters of the GFP for charmm force 
> field but I am not able to find it out how to add it to the charmm FF 
> file.. I have two files one is the topology file , which looks like this :- 
> 
> *
>    22    1
> MASS    13 CP2c   12.01100 C ! his CE1 carbon
> MASS    14 NR2c   14.00700 N ! neutral his unprotonated ring nitrogen
> MASS    15 NR1c   14.00700 N ! neutral his protonated ring nitrogen
> MASS    16 CP1c   12.01100 C ! his CG and CD2 carbons
> MASS    17 Och    15.99900 O ! carbonyl oxygen
> MASS    18 CE1c   12.01100 C ! for alkene; RHC=CR
> MASS    19 HA1c    1.00800 H ! for alkene; RHC=CR
> MASS    41 CA4    12.01100 C ! aromatic C
> MASS    42 HPc     1.00800 H ! aromatic H
> MASS    43 OHc    15.99900 O ! from OH1
> MASS    44 Hch     1.00800 H ! polar H
> MASS    45 CT3c   12.01100 C ! aliphatic sp3 C for CH3
> MASS    46 HAc     1.00800 H ! nonpolar H
> MASS    47 CA1    12.01100 C ! aromatic C
> MASS    48 CA2    12.01100 C ! aromatic C
> MASS    49 CA3    12.01100 C ! aromatic C
> 
> DECL -CA
> DECL -C
> DECL -O
> DECL +N
> DECL +HN
> DECL +CA
> DEFA FIRS NTER LAST CTER
> AUTO ANGLES DIHE
> 
> 
> AUTOGENERATE ANGLES DIHE
> DEFA FIRS NONE LAST NONE
> 
> RESI CRO  0.000
> GROUP                   ! Imidazolinone ring
> ATOM C1 CP2c  0.76
> ATOM N2 NR2c -0.55
> ATOM N3 NR1c -0.64
> ATOM C2 CP1c  0.80
> ATOM O2 Och  -0.61
> ATOM CA CP1c  0.24
> !
> GROUP                   ! Charges from propene
> ATOM CB CE1c -0.10
> ATOM HB HA1c  0.10
> !
> GROUP                   ! Tyr ring : charges from charmm22
> ATOM CG2 CA1   0.00
> ATOM CD1 CA2  -0.115
> ATOM HD1 HPc   0.115
> ATOM CD2 CA2  -0.115
> ATOM HD2 HPc   0.115
> ATOM CE1 CA3  -0.115
> ATOM HE1 HPc   0.115
> ATOM CE2 CA3  -0.115
> ATOM HE2 HPc   0.115
> ATOM CZ CA4    0.11
> ATOM OH Ohc   -0.54
> ATOM HH Hch    0.43
> !
> !Glycine part / C=O taken from Charmm22
> GROUP
> ATOM CAg  CT2    -0.18  !     |
> ATOM HA1  HB      0.09  !     |
> ATOM HA2  HB      0.09  ! HA1-CA-HA2
> GROUP                   !     |
> ATOM C    C       0.51  !     |
> ATOM O    O      -0.51  !     C=O
> !
> !Serine part / taken from Charmm22
> GROUP
> ATOM N    NH1    -0.47  !     |
> ATOM HN   H       0.31  !  HN-N
> ATOM CAs  CT1     0.07  !     |   HB1
> ATOM HA   HB      0.09  !     |   |
> GROUP                   !  HA-CA--CB--OG
> ATOM CBs  CT2     0.05  !     |   |     \
> ATOM HB1  HA      0.09  !     |   HB2    HG1
> ATOM HB2  HA      0.09  !   O=C
> ATOM OG1  OH1    -0.66  !     |
> ATOM HG1  H       0.43
> 
>  
> 
> 
> Other file is the parameter file :-
> 
> ! GFP Chromophore parameters, protonated form
> !
> BONDS
> !
> !V(bond) = Kb(b - b0)**2
> !
> !Kb: kcal/mole/A**2
> !b0: A
> !
> !atom type Kb          b0
> CA1  CA2   305.00      1.3750 !
> CA2  CA3   305.00      1.3750 !
> CA3  CA4   305.00      1.3750 !
> HPc  CA1   340.000     1.08   !
> HPc  CA2   340.000     1.08   !
> HPc  CA3   340.000     1.08   !
> HPc  CA4   340.000     1.08   !
> Ohc  Hch   545         0.96   ! 
> Ohc  CA4   334.3       1.4110 !
> HA1c CE1c  360.500     1.10   ! 
> NR1c CP1c  400.000     1.41   !
> NR1c CP2c  400.000     1.39   ! 
> NR2c CP2c  400.000     1.30   ! 
> NR2c CP1c  400.000     1.40   !
> CP1c CP1c  410.000     1.49   !
> CP1c CE1c  560         1.36   !
> CP1c Och   807         1.22   !
> CE1c CA1   370         1.45   !
> NR1c CT2   352         1.45   ! 
> CP2c CT1   320         1.49   ! 
> 
> 
> ANGLES
> !
> !V(angle) = Ktheta(Theta - Theta0)**2
> !
> !V(Urey-Bradley) = Kub(S - S0)**2
> !
> !Ktheta: kcal/mole/rad**2
> !Theta0: degrees
> !Kub: kcal/mole/A**2 (Urey-Bradley)
> !S0: A
> !
> !atom types     Ktheta    Theta0   Kub     S0
> !
> NR2c CP2c NR1c  130.00    114.00   ! 
> CP2c NR2c CP1c  130.00    106.00   ! 
> CP2c NR1c CP1c  130.00    107.90   ! 
> NR2c CP1c CP1c  130.00    108.30   ! 
> NR2c CP1c CE1c   45.80    129.50   ! 
> NR1c CP1c OcH    42.00    126.00   !
> NR1c CP1c CP1c  130.00    103.00   ! 
> OcH  CP1c CP1c   38.00    132.00   !
> CP1c CP1c CE1c   45.80    122.00   ! 
> CP1c CE1c CA1   130.00    130.00   ! 
> CP1c CE1c HA1c   42.00    114.00   ! 
> CE1c CA1  CA2    45.80     121.00   
> HA1c CE1c CA1    42.00     116.00   ! 
> CA1  CA2  CA3   40.000    120.00   35.00   2.41620
> CA2  CA1  CA2   40.000    120.00   35.00   2.41620
> CA2  CA3  CA4   40.000    120.00   35.00   2.41620
> CA3  CA4  CA3   40.000    120.00   35.00   2.41620
> !
> HPc  CA3  CA4   30.000    120.00   22.00   2.15250 
> HPc  CA3  CA2   30.000    120.00   22.00   2.15250
> HPc  CA2  CA3   30.000    120.00   22.00   2.15250
> HPc  CA2  CA1   30.000    120.00   22.00   2.15250
> !
> Ohc  CA4  CA3   45.200   120.0000 ! ALLOW   ARO ALC
> HcH  Ohc  CA4   65.000   108.0000 ! ALLOW   ALC ARO
> !
> !Connection to the ser fragment
> !------------------------------
> CT2  CT1  CP2c    52.000   108.0000 ! ALLOW   ALI PEP POL ARO
> HB   CT1  CP2c  50.000   109.5000 ! ALLOW  PEP
> NH1  CT1  CP2c  50.000   107.0000 ! ALLOW   PEP POL ARO ALI
> NR2C CP2C CT1   40.00    125.00   ! 
> NR1C CP2C CT1   35.00    121.40   ! 
> !
> !Connection to the gly fragment
> !------------------------------
> NR1C CT2  C     50.000   107.0000 
> NR1c CT2  HB     48.000   108.0000
> CP2C NR1C CT2   36.00    129.00
> CP1C NR1C CT2   32.00    123.40
> !
> DIHEDRALS
> !
> !V(dihedral) = Kchi(1 + cos(n(chi) - delta))
> !
> !Kchi: kcal/mole
> !n: multiplicity
> !delta: degrees
> !
> !atom types             Kchi    n   delta
> !
> CP2C NR2C CP1C CP1C    14.0000  2   180.00 ! 
> CP2C NR1C CP1C CP1C    14.0000  2   180.00 !
> NR2C CP2C NR1C CP1C    14.0000  2   180.00 !
> NR2C CP1C CP1C NR1C     4.0000  2   180.00 ! 
> NR1C CP2C NR2C CP1C     4.0000  2   180.00 ! 
> CA1  CA2  CA3  CA4      3.1000  2   180.00 ! 
> CA2  CA1  CA2  CA3      3.1000  2   180.00 ! 
> CA2  CA3  CA4  CA3      3.1000  2   180.00 ! 
> !OCh CAC  CAC  CAC      3.1000  2   180.00 ! 
> CA2  CA3  CA4  OhC      3.1000  2   180.00 ! 
> CA1  CA2  CA3  HPC      4.2000  2   180.00 ! 
> CA2  CA1  CA2  HPC      4.2000  2   180.00 ! 
> CA3  CA4  CA3  HPC      4.2000  2   180.00 ! 
> HPC  CA2  CA3  CA4      4.2000  2   180.00 ! 
> HPC  CA2  CA3  HPC      2.4000  2   180.00 ! 
> !HCH  OCh CAC  CAC      0.9900  2   180.00 ! 
> HCH  OhC CA4  CA3       0.9900  2   180.00 ! 
> HPC  CA3  CA4  OhC      4.2000  2   180.00 ! 
> !
> CP2C NR2C CP1C CE1C     3.000   2   180.00 ! 
> NR1C CP1C CP1C CE1C     3.00    2   180.00 ! 
> OCH  CP1C CP1C CE1C     2.00    2   180.00 ! 
> CE1C CA1  CA2  HPC      4.20    2   180.00 ! 
> CE1C CA1  CA2  CA3      3.10    2   180.00 ! 
> !
> !barrier CA-CB
> CP1C CP1C CE1C HA1C     6.84   2   180.00 ! 
> CP1C CP1C CE1C CA1      6.84   2   180.00 !
> NR2C CP1C CE1C HA1C     6.84   2   180.00 !
> NR2C CP1C CE1C CA1      6.84   2   180.00 ! 
> !
> !barrier CB-CG2
> CP1C CE1C CA1  CA2      1.4  2   180.00 !  
> HA1C CE1C CA1  CA2      1.4  2   180.00 ! 
> !
> CP2C NR1C CP1C OCH      14.00    2   180.00 !
> NR2C CP2C NR1C CT2      14.00    2   180.00 !
> NR2C CP1C CP1C OCH      14.00    2   180.00 !
> CP1C NR1C CP2C CT1      14.00    2   180.00 !
> OCH  CP1C NR1C CT2      14.00    2   180.00 !
> CP1C NR2C CP2C CT1      14.00    2   180.00 !
> CP1C CP1C NR1C CT2      14.00    2   180.00 !
> CT1  CP2C NR1C CT2      14.00    2   180.00 !
> !
> ! Linking the chromophore and the glycine fragment
> O    C    CT2  NR1C      0.0000  1     0.00 !   
> NH1  C    CT2  NR1c       0.6000  1     0.00 !  
> CP2C NR1C CT2 HB         0.032  3     0.00 ! 
> CP2c NR1c CT2 C          0.032  3     0.00 !
> CP1c NR1c CT2 HB         0.032  3   180.00 !
> CP1c NR1c CT2 C          0.032  3   180.00 !
> !
> ! Linking the chromophore and the serine fragment
> C    NH1  CT1  CP2C      0.2000  1   180.00 !
> H    NH1  CT1  CP2C      0.0000  1     0.00 !
> NR2C CP2C CT1 HB         0.105   3   180.00 ! 
> NR2C CP2C CT1 NH1        0.105   3   180.00 ! 
> NR2C CP2C CT1 CT2        0.105   3   180.00 ! 
> NR1C CP2C CT1 HB         0.105   3     0.00 ! 
> NR1C CP2C CT1 NH1        0.105   3     0.00 ! 
> NR1C CP2C CT1 CT2        0.105   3     0.00 ! 
> 
> 
> IMPROPER
> !
> !V(improper) = Kpsi(psi - psi0)**2
> !
> !Kpsi: kcal/mole/rad**2
> !psi0: degrees
> !note that the second column of numbers (0) is ignored
> !
> !atom types           Kpsi                   psi0
> !
> CP2C NR2C NR1C CT1      0.5       0           0.00
> CP2C NR1C NR2C CT1      0.5       0           0.00
> !
> CP1C NR1C CP1C OCH       0.5       0           0.00
> CP1C CP1C NR1C OCH       0.5       0           0.00
> !
> NR1C CP1C CP2C CT2      0.45       0           0.00 
> NR1C CP2C CP1C CT2      0.45       0           0.00  
> !
> CP1C NR2C CP1C CE1C   220.0       0           0.00
> CP1C CP1C NR2C CE1C   220.0       0           0.00
> !
> CE1C CP1C CA1  HA1C    30.0        0           0.00
> CE1C CA1  CP1C HA1C    30.0        0           0.00
> 
> 
> Can anybody jus tell it how to do .. as I have posted this question 
> earlier in the forum and got chapter 5 to read as suggestion ?? ... but 
> I am a bit confused ...how to do it 
> 
> -- 
> Bharat
> Ph.D. Candidate
> Room No. : 7202A, 2nd Floor
> Biomolecular Engineering Laboratory
> Division of Chemical Engineering and Polymer Science
> Pusan National University
> Busan -609735
> South Korea
> Lab phone no. - +82-51-510-3680, +82-51-583-8343
> Mobile no. - 010-5818-3680
> E-mail : monu46010 at yahoo.com <mailto:monu46010 at yahoo.com>
> 

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

Justin A. Lemkul
Ph.D. Candidate
ICTAS Doctoral Scholar
MILES-IGERT Trainee
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin

========================================



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