Available in the following product(s): ICM-Pro | ICM-VLS |

To perform constrained docking to a template structure you need to position the template in the desired position in the receptor - this can be done by docking or using the connect option if the template is not already in the correct position.

Some considerations for the template:

• The template needs to be an ICM object.
• Make sure the template contains only the atoms you wish to match - a template can be edited by right clicking on it in the ICM Workspace and select Edit/ Edit Compound.
• It is also important to delete hydrogen atoms on the template particulalry in places where substituent groups will be placed.

• Setup the docking project as described in the Small Molecule Docking chapter.
• Before starting the docking select Docking/Template
• Read in the ICM object that you wish to use as a template. Select the template object name in the Object data entry box using the drop down button.
• Select the template match method. Match by atom name, substructure (option requires that template is an exact substructure of input ligands. If it does not match then no tethers will be imposed for that particular ligand.) , fuzzy (option will find maximum common substructure between template and input ligands. The matched atoms will be tethered during the simulation.) or APF (option will build APF maps of the template and use them in simulation and addition to receptor maps. This options does not require substruture and common substruture between template and input ligands.).

• Click OK
• Set the docking job running - Docking/Run Docking Batch

How to weight the strength of the APF field.

Template strength can be regulated (even down to individual atoms) by setting occupancies. Load the template(s) from PROJNAME_tmplt.ob , reset occupancies as described below and write it back.

In GUI one can select molecule (or individual atoms), right click on it in 3D window and select Edit/Occupancy in the pop-up menu.

Alternatively in the the command line:

set occupancy a_//  0.1