Difference between revisions of "2016 DOCK tutorial with Beta Trypsin"

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(Box Generation)
(Grid computing)
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=== Grid computing===
 
=== Grid computing===
first, create an input file for sphgen to read.
+
Since the electronic interactions between two objects in space can be decomposed into pairwise interactions, it is highly efficient to fully calculate a proteins electric contribution to binding energy before DOCKing a ligand.
  
vim INSPH
+
switch to the 03.box-grid/ directory
  
The file should have the following information. Remember that
+
cd 03.box-grid/
 +
 
 +
create an input file named showbox.in
 +
 
 +
vim showbox.in
 +
 
 +
enter the following information
 +
 
 +
  Y                                              # Do you want to calculate a box? (YES)
 +
  8.0                                            # How long should the box length be?
 +
  ../02.surface-spheres/selected_spheres.sph      # which sphere file is our input?
 +
  1                                              # How many clusters for the file?
 +
  1BJU.box.pdb                                    # What do we want to name the output file?
 +
 
 +
save the file, then enter the following command to generate the box
 +
 
 +
showbox > showbox.in
 +
 
 +
The box can be visualized in Chimera by loading the output_spheres_selected.pdb file, then loading the 1BJU.box.pdb file
 +
 
 +
Next, we will calculate the grid energies
  
 
==V. Docking a Single Molecule for Pose Reproduction==   
 
==V. Docking a Single Molecule for Pose Reproduction==   

Revision as of 14:45, 26 March 2016

For additional Rizzo Lab tutorials see DOCK Tutorials. Use this link Wiki Formatting as a reference for editing the wiki. This tutorial was developed collaboratively by the AMS 536 class of 2014, using DOCK v6.6.

I. Introduction

Yaping She & Omar Sanchez Reyes

DOCK

Beta Trypsin

Organizing Directories

II. Preparing the Receptor and Ligand

Beilei Jiang

III. Generating Receptor Surface and Spheres

Lauren Prentis

Generating the Receptor Surface

Placing Spheres

IV. Generating Box and Grid

Monaf Awwa

Box Generation

>Start Chimera and open the RECEPTOR files 1BJU.rec.noH.pdb Next, select the ACTION subheader, then select SURFACE, then SHOW

Once you can see the van der Waals surface of the protein, select the TOOLS subheader, then STRUCTURE EDITING, and lastly select WRITE DMS and save the file as 1BJU.dms

Now that we have a surface, we can more effectively calculate regions of the protein where a small molecule can bind. To further accelerate calculations, we will specify which atoms to calculate the interactions for via the program sphgen

Switch over to the 02.surfacespheres directory with the following command

cd 02.surfacespheres

Next, create an input file for sphgen to read.

vim INSPH

The file should have the following information

1BJU.rec.dms #the file corresponding to the surface is the input file R #we want the spheres outside the protein surface X #we want all subsets of spheres to be generated 0.0 #default size of proteins with surface contacts 4.0 #default maximum of the sphere radius generated (Angstroms) 1.4 #default minimum of the sphere radius generated (Angstroms) Also corresponds to probe radius 1BJU.rec.sph #output file name

Now we can enter the command to run sphgen

sphgen -i INSPH -o OUTSPH

Once completed, check the OUTSPH file to ensure no errors occured

If you'd like to visually inspect the spheres generated, start Chimera and load the 1BJU.rec.mol2 file, then load the 1BJU.rec.sph file.

Now we will use the showsphere program to convert our .sph file back to a .pdb format.

In the same directory, enter the command

showsphere

The following questions will appear. Answer as follows

Enter name of sphere cluster file:

    1BJU.rec.sph

Enter cluster number to process (<0 = all):

    -1

Generate surfaces as well as pdb files (<N>/Y)?

    N

Enter name for output file prefix:

    output_spheres

Process cluster 0 (contains ALL spheres) (<N>/Y)?

    N

You should now have a file named output_spheres.pdb in your directory. You can visualize the spheres by loading chimera and the 1BJU.rec.noH.mol2, then loading the output_spheres.pdb file.

For the docking calculation, we are most interesting in a subset of the spheres. To select the spheres most important to ligand binding, we will use the command

sphere_selector 1BJU.rec.sph ../01.dockprep/1BJU.lig.mol2 8.0

The 8.0 Angstrom value indicates we want to select spheres within 8 angstroms of our ligand. This hypothetically means we are designing a competitive inhibitor.

Now lets create the proper output file for our spheres. Enter the command

showsphere

and answer the following questions

Enter name of sphere cluster file:

    selected_spheres.sph

Enter cluster number to process (<0 = all):

    -1

Generate surfaces as well as pdb files (<N>/Y)?

    N

Enter name for output file prefix:

    output_spheres_selected

Process cluster 0 (contains ALL spheres) (<N>/Y)?

    N

This will ensure the docking calculation samples the most important regions of the protein surface

Grid computing

Since the electronic interactions between two objects in space can be decomposed into pairwise interactions, it is highly efficient to fully calculate a proteins electric contribution to binding energy before DOCKing a ligand.

switch to the 03.box-grid/ directory

cd 03.box-grid/

create an input file named showbox.in

vim showbox.in

enter the following information

  Y                                               # Do you want to calculate a box? (YES)
  8.0                                             # How long should the box length be?
  ../02.surface-spheres/selected_spheres.sph      # which sphere file is our input?
  1                                               # How many clusters for the file?
  1BJU.box.pdb                                    # What do we want to name the output file?

save the file, then enter the following command to generate the box

showbox > showbox.in

The box can be visualized in Chimera by loading the output_spheres_selected.pdb file, then loading the 1BJU.box.pdb file

Next, we will calculate the grid energies

V. Docking a Single Molecule for Pose Reproduction

Agatha Lyczek & Haoyue Guo

Minimization

Dock Minimization Input file: min.in

conformer_search_type                                        rigid
use_internal_energy                                          yes
internal_energy_rep_exp                                      12
ligand_atom_file                                             ../01.dockprep/1BJU.lig.mol2
limit_max_ligands                                            no
skip_molecule                                                no
read_mol_solvation                                           no
calculate_rmsd                                               yes
use_rmsd_reference_mol                                       yes
rmsd_reference_filename                                      ../01.dockprep/1BJU.lig.mol2
use_database_filter                                          no
orient_ligand                                                no
bump_filter                                                  no
score_molecules                                              yes
contact_score_primary                                        no
contact_score_secondary                                      no
grid_score_primary                                           yes
grid_score_secondary                                         no
grid_score_rep_rad_scale                                     1
grid_score_vdw_scale                                         1
grid_score_es_scale                                          1
grid_score_grid_prefix                                       ../03.box-grid/1BJU.grid
multigrid_score_secondary                                    no
dock3.5_score_secondary                                      no
continuous_score_secondary                                   no
footprint_similarity_score_secondary                         no
ph4_score_secondary                                          no
descriptor_score_secondary                                   no
gbsa_zou_score_secondary                                     no
gbsa_hawkins_score_secondary                                 no
SASA_descriptor_score_secondary                              no
amber_score_secondary                                        no
minimize_ligand                                              yes
simplex_max_iterations                                       1000
simplex_tors_premin_iterations                               0
simplex_max_cycles                                           1
simplex_score_converge                                       0.1
simplex_cycle_converge                                       1.0
simplex_trans_step                                           1.0
simplex_rot_step                                             0.1
simplex_tors_step                                            10.0
simplex_random_seed                                          0
simplex_restraint_min                                        yes
simplex_coefficient_restraint                                10.0
atom_model                                                   all
vdw_defn_file                                                ../zzz.parameters/vdw.defn
flex_defn_file                                               ../zzz.parameters/flex.defn
flex_drive_file                                              ../zzz.parameters/flex_drive.tbl
ligand_outfile_prefix                                        1BJU.min
write_orientations                                           no
num_scored_conformers                                        1
rank_ligands                                                 no

Result:

Minimization result;RMSD = 0.3177; blue: experiment; green: predicted

Rigid docking

To run the input file:

dock6 -i rigid_nr.in

Rigid docking input file: rigid_nr.in

conformer_search_type                                        rigid
use_internal_energy                                          yes
internal_energy_rep_exp                                      12
ligand_atom_file                                             ../01.dockprep/1BJU.lig.mol2
limit_max_ligands                                            no
skip_molecule                                                no
read_mol_solvation                                           no
calculate_rmsd                                               yes
use_rmsd_reference_mol                                       yes
rmsd_reference_filename                                      ../01.dockprep/1BJU.lig.mol2
use_database_filter                                          no
orient_ligand                                                yes
automated_matching                                           yes
receptor_site_file                                           ../02.surface-sphere/selected_spheres.sph
max_orientations                                             1000
critical_points                                              no
chemical_matching                                            no
use_ligand_spheres                                           no
bump_filter                                                  no
score_molecules                                              yes
contact_score_primary                                        no
contact_score_secondary                                      no
grid_score_primary                                           yes
grid_score_secondary                                         no
grid_score_rep_rad_scale                                     1
grid_score_vdw_scale                                         1
grid_score_es_scale                                          1
grid_score_grid_prefix                                       ../03.box-grid/1BJU.grid
multigrid_score_secondary                                    no
dock3.5_score_secondary                                      no
continuous_score_secondary                                   no
footprint_similarity_score_secondary                         no
ph4_score_secondary                                          no
descriptor_score_secondary                                   no
gbsa_zou_score_secondary                                     no
gbsa_hawkins_score_secondary                                 no
SASA_descriptor_score_secondary                              no
amber_score_secondary                                        no
minimize_ligand                                              yes
simplex_max_iterations                                       1000
simplex_tors_premin_iterations                               0
simplex_max_cycles                                           1
simplex_score_converge                                       0.1
simplex_cycle_converge                                       1.0
simplex_trans_step                                           1.0
simplex_rot_step                                             0.1
simplex_tors_step                                            10.0
simplex_random_seed                                          0
simplex_restraint_min                                        yes
atom_model                                                   all
vdw_defn_file                                                ../zzz.parameters/vdw.defn
flex_defn_file                                               ../zzz.parameters/flex.defn
flex_drive_file                                              ../zzz.parameters/flex_drive.tbl
ligand_outfile_prefix                                        1BJU.rigid_nr
write_orientations                                           no

Best scored rigid docking result:

Rigid docking result;RMSD = 0.7946; blue: experiment; pink: predicted

Flexible Docking

To run the input file:

dock6 -i flex.in

Flexible docking input file: flex.in

conformer_search_type                                        flex
user_specified_anchor                                        no
limit_max_anchors                                            no
min_anchor_size                                              5
pruning_use_clustering                                       yes
pruning_max_orients                                          1000
pruning_clustering_cutoff                                    100
pruning_conformer_score_cutoff                               100.0
use_clash_overlap                                            no
write_growth_tree                                            no
use_internal_energy                                          yes
internal_energy_rep_exp                                      12
ligand_atom_file                                             ../01.dockprep/1BJU.lig.mol2
limit_max_ligands                                            no
skip_molecule                                                no
read_mol_solvation                                           no
calculate_rmsd                                               yes
use_rmsd_reference_mol                                       yes
rmsd_reference_filename                                      ../01.dockprep/1BJU.lig.mol2
use_database_filter                                          no
orient_ligand                                                yes
automated_matching                                           yes
receptor_site_file                                           ../02.surface-sphere/selected_spheres.sph
max_orientations                                             1000
critical_points                                              no
chemical_matching                                            no
use_ligand_spheres                                           no
bump_filter                                                  no
score_molecules                                              yes
contact_score_primary                                        no
contact_score_secondary                                      no
grid_score_primary                                           yes
grid_score_secondary                                         no
grid_score_rep_rad_scale                                     1
grid_score_vdw_scale                                         1
grid_score_es_scale                                          1
grid_score_grid_prefix                                       ../03.box-grid/1BJU.grid
multigrid_score_secondary                                    no
dock3.5_score_secondary                                      no
continuous_score_secondary                                   no
footprint_similarity_score_secondary                         no
ph4_score_secondary                                          no
descriptor_score_secondary                                   no
gbsa_zou_score_secondary                                     no
gbsa_hawkins_score_secondary                                 no
SASA_descriptor_score_secondary                              no
amber_score_secondary                                        no
minimize_ligand                                              yes
minimize_anchor                                              yes
minimize_flexible_growth                                     yes
use_advanced_simplex_parameters                              no
simplex_max_cycles                                           1
simplex_score_converge                                       0.1
simplex_cycle_converge                                       1.0
simplex_trans_step                                           1.0

Best scored flexible docking result:

Flexible docking result;RMSD = 0.45; blue: experiment; pink: predicted

VI. Virtual Screening

Katie Maffucci

DOCK Preparation

Post Processing

VIII. Frequently Encountered Problems

EVERYONE