A Chemist’s Guide to Maestro
Tutorial Created with Software Release: 2024-1
Topics: Hit-to-Lead & Lead Optimization , Medicinal Chemistry Design , Small Molecule Drug Discovery
Products Used: Ligand Designer , Maestro
|
0.3 MB |
This tutorial is written for use with a 3-button mouse with a scroll wheel.
Words found in the Glossary of Terms are shown like this: Workspacethe 3D display area in the center of the main window, where molecular structures are displayedthe 3D display area in the center of the main window, where molecular structures are displayed
Abstract:
This tutorial will explore a selection of tasks in Maestro that could be useful for chemists during the idea generation and lead optimization stages of their projects.
Tutorial Content
1. Creating Projects and Importing Structures
At the start of the session, change the file path to your chosen Working Directorythe location that files are saved in Maestro to make file navigation easier. Each session in Maestro begins with a default Scratch Projecta temporary project in which work is not saved, closing a scratch project removes all current work and begins a new scratch project, which is not saved. A Maestro project stores all your data and has a .prj extension. A project may contain numerous entries corresponding to imported structures, as well as the output of modeling-related tasks. Once a project is created, the project is automatically saved each time a change is made.
Structures can be imported from the PDB directly, or from your Working Directorythe location that files are saved using File > Import Structures, and are added to the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion and Project Tabledisplays the contents of a project and is also an interface for performing operations on selected entries, viewing properties, and organizing structures and data. The Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion is located to the left of the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed. The Project Tabledisplays the contents of a project and is also an interface for performing operations on selected entries, viewing properties, and organizing structures and data can be opened by Ctrl+T (Cmd+T) or Window > Project Table if you would like to see an expanded view of your project data.
-
Double-click the Maestro icon.
- (No icon? See Starting Maestro)
- Go to File > Change Working Directory
- Find your directory, and click Choose.
- Pre-generated input and results files are included for running jobs or examining output. Download the zip file here: https://www.schrodinger.com/sites/default/files/s3/release/current/Tutorials/zip/achemistsguidetomaestro.zip
- After downloading the zip file, unzip the contents in your Working Directorythe location that files are saved for ease of access throughout the tutorial.
- Go to File > Save Project As
- Change the File name to Maestro_chemist.
-
Click Save.
-
The project is now named
Maestro_chemist.prj.
-
The project is now named
- Go to File > Import Structures
-
Select
1fjs_prep_lig.mae, 4TVG.pdb, 4TVH.pdb, 4Z4X.pdb, LigandMCMM.mae -
Click Open.
- Structures are added in the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion.
PDB files can be imported directly into Maestro by navigating to File > Import PDB and filling in file information. To save time, we have provided a series of structures.
- Navigate to Workspace > Customize Mouse Actions
- Choose your appropriate mouse or trackpad preferences from the dropdown and read through the corresponding mouse actions.
2. Creating and Modifying Molecules
Maestro employs a “select(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries first” paradigm where an object must be selected(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries before an operation is performed on it. In this section, we will cover different methods of copying molecules into and out of the Maestro interface. Then, we will save an image of the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed to your Working Directorythe location that files are saved. Finally, we will make modifications to an existing ligand. Please refer to the Glossary of Terms for the difference between selecting and including structures.
2.1 Copy and paste structures
- Includethe entry is represented in the Workspace, the circle in the In column is blue 1fjs_prep_lig in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
-
Under Quick Select, click L.
- The ligand is highlighted.
-
Go to Edit > Copy
- The SMILES string of the ligand is ready to be pasted into an external document.
-
Go to Edit > Paste Special > By Placing
- A banner appears.
-
Click in the Workspace.
- A copy of the ligand is pasted into the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
-
Click X to close the banner.
- Pasting function stops.
Banners appear to prompt an action or to provide a notification.
- Under Quick Select, click Clear selection.
- Type Z to fit structures to the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
-
Click Workspace > Save Image As
- The Save Image panel opens.
- Click Options >> to expand image details.
- Check Transparent background and 300 DPI.
- Change File name to 1fjs_ligands.
-
Click Save.
-
A
.pngimage of the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed is saved to your Working Directorythe location that files are saved.
-
A
Note: If an item is highlighted in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed, the image will be saved with the selection highlights.
Go to Tasks > Browse > Workspace Operations for more options, such as Ray Trace for high-quality images.
2.2 Create a new entry
- Includethe entry is represented in the Workspace, the circle in the In column is blue LigandMCMM in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
Note: Fill in the blue circle to includethe entry is represented in the Workspace, the circle in the In column is blue an Entry in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed. Included entries can be interacted with. Selected Entries have the Title highlighted in blue. Typically this is done when preparing for a computational task.
-
Under Quick Select, click L.
- The ligand is highlighted.
-
Click Build.
- The 3D Builder panel opens.
Note: The 3D Builder panel can be moved by clicking and dragging on the panel name.
Hover over buttons in 3D Builder to see a tooltip about their function. Many tools in Maestro have tooltips and/or links to the help section in the documentation.
-
Choose Copy selected atoms to new entry.
- A banner appears.
-
Change Entry title to ligand_copy and click the check.
- A new entry ligand_copy is created in the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion.
- Includethe entry is represented in the Workspace, the circle in the In column is blue ligand_copy in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- Use click and drag to select(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries the piperidine group.
Note: If in Trackpad/PyMOL mode, use shift-click and drag to select(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries items in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- Click a hydrogen on the terminal carbon.
Note: Use predictive highlighting to help when selecting items in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed before you commit to the selection by hovering over the atom of interest.
-
In 3D Builder, click Add Fragments.
- The Fragments pane opens.
-
Choose cyclopentadiene.
- A cyclopentadiene fragment is appended to the molecule in place of the selected(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries hydrogen.
- Next to the attached fragment, click the Edit Fragment four-line icon.
-
Choose Change Connection Point.
- Possible connection points are highlighted.
-
Click the sp3 carbon.
- The new connection point is marked with a green check.
- Close the 3D Builder.
Optional: Select Measure in the favorites toolbar to measure bond distances and angles.
Optional: Rotate dihedrals using the 3D Builder by selecting from the Move dropdown menu.
Hovering over the sp3 carbon will allow you to choose which hydrogen position to set as the connection.
3. Drawing Structures
In this section, we will explore ways to draw molecules in 2D and 3D form. We will use the 2D Sketcher to modify an existing entry and create a new fragment. Then, we will make a copy of an entry to use as a template to create new molecules, using the 3D Builder’s Draw function. Finally, a fragment made in the 2D Sketcher will be added to a molecule in the 3D Workspacethe 3D display area in the center of the main window, where molecular structures are displayed and the new structure will be minimized.
3.1 Create structures in 2D
- Includethe entry is represented in the Workspace, the circle in the In column is blue ligand_copy in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
-
Right-click on the 2D Overlay and choose View in 2D Sketcher.
- The 2D Workspace - 2D Sketcher opens.
- If the 2D Overlay is not visible in your workspace, turn it on before proceeding with the previous step by clicking Window > 2D Overlay.
Note: Right-clicking is a functionality present in many different panels and areas of Maestro.
Optional: Read through the lists of options that appear as they can contain useful shortcuts.
-
Choose N and click both hydroxyl groups.
- The hydroxyl groups are changed to amines.
- Click Save as New.
-
Name the Entry ligand_2DSketcher.
- A new ligand is added to the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion with these modifications.
- The Workspacethe 3D display area in the center of the main window, where molecular structures are displayed is rendered in a wire representation.
- Close the 2D Sketcher.
These modifications can also be performed by selecting the connection points and using Shift+N with the 3D Builder panel open.
The 2D Sketcher can also be used to update existing entries in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed by selecting Update Entry.
-
Double-click Presets.
- The ligand is rendered as ball and stick.
- Go to Workspace > Clear Workspace
Note: You can also right-click on empty Workspacethe 3D display area in the center of the main window, where molecular structures are displayed and choose Clear Workspace.
-
Go to Edit > 2D Sketcher
- The 2D Workspace - 2D Sketcher opens.
- You are still in Draw Mode.
- In 2D Workspace - 2D Sketcher, click benzene and click in the 2D Workspace.
-
Draw this structure.
- To add the alkyne, you may type “3” when hovering over an alkane, or use the alkyne drawing tool.
- Click the green check mark indicating Cleanup to fix bond angles.
- Click Save as New and change the Input Entry Title to fragment.
-
Click OK.
- A new entry titled fragment is saved to the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion.
- The fragment is shown in 3D in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
Ctrl-Z (Cmd-Z) will undo previous steps in the 2D Sketcher. This feature is not yet available in all areas of Maestro.
- Right-click on the alkyne bond.
-
Choose Decrease Bond Order.
- The alkyne is now an alkene.
-
Under Quick Select, click All.
- The fragment is highlighted.
-
Type Ctrl+M (Cmd-M) to minimize the selection.
- The fragment is minimized.
Minimizing selected(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries atoms can also be accessed in the 3D Builder or the Favorites Toolbar or Edit > Minimize.
3.2 Create structures in 3D
- Right-click on ligand_2DSketcher in the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion.
- Choose Duplicate > In Place
- Double click on the second ligand_2DSketcher entry and change the title to ligand1.
- Includethe entry is represented in the Workspace, the circle in the In column is blue ligand1 in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- In 3D Builder, click Add Fragments and choose a fragment of your choice.
Note: If you wish to explore all fragments included in the 3D Builder please click the three dots. You may also choose to create your own fragment library or click the pencil icon to draw directly on the 3D structure.
Note: The fragment shown in this example is a cyclopropane.
Using Ctrl-M can perform a quick minimization. It is worth noting that minimizing the structure is less accurate than performing a Jaguar Optimization on your molecule.
- Shift-click to select an aniline carbon on the ligand and a fragment atom.
-
Right-click on one of the selected atoms and choose Add Bond.
- Your fragment is now attached to the ligand.
- Minimize this structure by selecting the whole molecule and clicking Minimize Selected Atoms in the Favorites Toolbar.
- Close the 3D Builder Panel.
Note: If in Trackpad/PyMOL mode, use shift-click and drag to draw bonds.
4. Generating and Visualizing Ligand Conformations
When working with small molecules in Maestro, it is easy to explore the conformational space of a molecule and visualize the results by aligning the conformations to a user-specified ‘core.’ In this section, we will generate conformations of the small molecule 1FJS_ prep_lig, using MacroModel. We will then use the superposition tool to overlay the conformations to a rigid, common core motif. The core will be defined using a SMARTS pattern generated from the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed structure.
4.1 Generate conformations
- Includethe entry is represented in the Workspace, the circle in the In column is blue 1fjs_prep_lig in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- Click R on your keyboard to switch to Residue selection mode.
- Click on an atom of a copy of the ligand to select the structure.
Note: This ligand was copied earlier in Section 2.1. The copied structures need to be removed before the conformational search.
-
Right click on the selected ligand.
- The Multiple Atoms Selected menu opens.
-
Choose Delete Atoms.
- The ligand is deleted from the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- Ensure only one ligand structure is includedthe entry is represented in the Workspace, the circle in the In column is blue in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- Go to Tasks and type Advanced Search.
-
Click on Advanced Search in the displayed results.
- The Conformational Search panel opens.
- For Use structures from, choose Workspace (included entries).
- Click the Mini tab.
- Set Maximum iterations to 100.
- Change Job name to mmod_csearch_1fjs.
-
Click Run.
- This job takes ~2 minutes.
- A banner appears when the job is incorporated.
- A new group titled mmod_csearch_1fjs-out is added to the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion.
4.2 Align the conformations
-
Click the mmod_csearch_1fjs-out group.
- All entries are selected(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries.
- Includethe entry is represented in the Workspace, the circle in the In column is blue the first 1fjs_prep_lig entry.
-
Go to Tasks > Browse > Structure Alignment > Superposition
- The Superposition panel opens.
- For Entries to superimpose, choose Project Table (selected).
- For Reference structure, choose 1fjs_prep_lig.
- Check Add property to Project Table.
- For Choose method, select Substructures.
- For Define structures for superposition using, choose SMARTS.
Note: In case you are still in Residue selection mode, type A on your keyboard to switch to Atom selection mode.
- In the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed, use shift-click to select(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries the atoms of the pyridine and the two fluorines.
-
In the Superposition panel, click Get from Selection.
- The SMARTS pattern is generated.
-
Click Superimpose Structures.
- RMSD properties are calculated.
Note: Click the Table icon in the upper right corner of the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed to view the RMSD values in the Project Tabledisplays the contents of a project and is also an interface for performing operations on selected entries, viewing properties, and organizing structures and data.
- Right-click the mmod_csearch_1fjs-out group and choose Include.
-
Click Continue in the Warning window.
- The conformations are superimposed in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- Conformations are aligned to the pyridine.
- Close the Superposition panel.
5. Small Molecule Alignment
Comparing two structurally similar small molecules can be useful for idea generation. In this section, we will superimpose two ligands, with and without a protein structure. We will begin by aligning two ligands using an automated method, then a manual method, and finally a flexible alignment method. Finally, we will superimpose an unbound ligand onto a ligand bound to a receptor. This is helpful for evaluating how a ligand could fit in a known binding site, without using docking, to assist with lead optimization.
5.1 Superimpose two distinct ligands
- Includethe entry is represented in the Workspace, the circle in the In column is blue LigandMCMM in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- Create a new entry of only the ligand titled ligand_phenol.
Note: See section 2.2 for details on creating a new entry.
- Includethe entry is represented in the Workspace, the circle in the In column is blue and select(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries ligand_phenol.
- Ctrl-click (Cmd-click) to includethe entry is represented in the Workspace, the circle in the In column is blue and select(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries 1fjs_prep_lig.
-
Go to Tasks > Browse > Structure Alignment > Quick Align
- The ligands are aligned.
- Type Z to fit ligands to the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- Includethe entry is represented in the Workspace, the circle in the In column is blue LigandMCMM.
- Create a new entry of only the ligand titled ligand_phenol2.
- Ctrl-click (Cmd-click) to includethe entry is represented in the Workspace, the circle in the In column is blue both 1fjs_prep_lig and ligand_phenol2.
Note: Use the Move Atoms function to move the ligands closer, if desired. See Section 3.2 for more details.
-
Go to Tasks > Structure Alignment > Superposition
- The Superposition panel opens.
- For Superimpose entries from, choose Workspace.
- For Reference structure, choose ligand_phenol2.
- Click the Atom pairs option.
Note: The order of atom selection is important, always start a pair from the same molecule.
-
Click the sulfur of ligand_phenol2.
- The sulfur is highlighted with a pink box.
-
Click the oxygen 1 of 1fjs_prep_lig.
- An orange line connects the atoms.
Figure 5-7. Selected atom pairs for superposition. Ligand_phenol2 is shown in green (right) and 1fjs_prep_lig is in gray (left).
- Click the carbon 5 of ligand_phenol2.
- Click the carbon 6 of 1fjs_prep_lig.
- Click the carbon 4 of ligand_phenol2.
- Click the carbon 1 of 1fjs_prep_lig.
-
Click Superimpose Structures.
- The ligands are superimposed.
- Use Move in the 3D Builder to break the alignment.
- Ctrl-click (Cmd-click) to select(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries both 1fjs_prep_lig and ligand_phenol2.
-
Go to Tasks > Browse > Structure Alignment > Ligand Alignment
- The Ligand Alignment panel opens.
- For Align ligands from, choose Project Table.
- For Reference, choose User-specified.
- Under Reference, choose 1fjs_prep_lig.
- Under Conformation, select Constrain common substructure and choose Largest common Bemis-Murcko scaffold.
- Set Job name to align_ligands_1fjs.
-
Click Run.
- This job takes a few seconds.
- The align_ligands_1fjs group is added to the Entry List.
Note: At this point, you can inspect the alignment, and consider altering the parameters until you get something more preferable.
5.2 Superimpose a ligand and a protein-ligand complex
- Includethe entry is represented in the Workspace, the circle in the In column is blue Ligand MCMM.
-
In the Favorites Toolbar, click Surface (Binding Site).
- The Create Binding Site Surfaces panel opens.
- For Surface type, choose Molecular Surface.
Note: The Interaction Map allows you to add a SiteMap surface map to your binding site.
- For Truncate receptor surface at, type 7.0 Å from ligand.
- For Color scheme, choose Electrostatic Potential.
-
Click OK.
- A surface is added to the protein.
- An ‘S’ is next to the entry.
- Ctrl-click (Cmd-click) to includethe entry is represented in the Workspace, the circle in the In column is blue 1fjs_prep_lig.
-
Under Quick Select, click L.
- Both ligands are selected (1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entriesin the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
-
Go to Tasks > Browse > Structure Alignment > Superposition
- The Superposition panel opens.
- For Superimpose entries from, choose Workspace.
- For Reference structure, choose LigandMCMM.
- For Choose method, choose Substructures.
- For Define structures for superposition using, choose ASL.
- Click Load Selection.
-
Click Superimpose Structures.
- 1fjs_prep_lig is aligned to the ligand of LigandMCMM.
Figure 5-14. 1fjs_prep_lig (gray) is aligned to the receptor-bound ligand (green). Ligand surface is toggled off.
- Type L to zoom to the ligands.
Note: You may choose to toggle off the surface for the Ligand. Click S and toggle off the Ligand surface.
This is not an accurate or rigorous way to evaluate how well a modified ligand will fit into a binding pocket. Visualizing a modified version of a known binder in a binding pocket should be only used to give you a crude sense of the possibility of your design fitting in the binding pocket. The conformational search, scoring function, and post-docking minimization included in the docking protocol lead to predictions that are considerably more accurate than simply overlaying ligands in the binding pocket.
6. Protein Alignment
Aligning proteins can give a better understanding of ligand SAR. In this section, we will align three HIV proteases by tertiary structure in order to visualize their similarities and differences. Then, we will align proteins by the binding site in order to compare the area closer to the cognate ligand.
6.1 Align proteins by tertiary structure
- Shift-click to includethe entry is represented in the Workspace, the circle in the In column is blue entries 4TVG, 4TVH, 4Z4X in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- In the Workspace Configuration Toolbar, click ➕.
-
Click Tile.
- The Workspacethe 3D display area in the center of the main window, where molecular structures are displayed is tiled by entry to show all three proteins separately.
-
Under Quick Select, click P.
- Proteins are selected(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries.
- Type Z.
- Click the Style button.
-
Click Undisplay selected atoms.
- The proteins residues are hidden.
-
Click Ribbons.
- Ribbons are added to the protein structures.
- Under Edit Ribbon, change the Color Scheme to Entry.
- In the Workspace Configuration Toolbar, click ➕.
- Click the Tile by button to turn off the tiling.
-
Type Z.
- The Workspacethe 3D display area in the center of the main window, where molecular structures are displayed is zoomed to the entries.
-
Go to Tasks > Browse > Structure Alignment > Protein Structure Alignment
- The Protein Structure Alignment panel opens.
- Under Use proteins from, choose Workspace (included entries).
- Uncheck Pick.
-
Click Align.
- The Protein Structure Alignment Results panel opens.
- Protein sequences, Alignment Scores, and RMSDs are shown.
6.2 Align proteins by binding site
-
Go to Tasks > Browse > Structure Alignment > Binding Site Alignment
- The Align Binding Sites panel opens.
- In the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion, shift-click to select(1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries entries 4TVG and 4TVH.
- For Use proteins from, choose Workspace (2 included entries).
- Change Job name to align_binding_sites_2proteins.
-
Click Run.
- This job takes ~1 minute.
- A new group is appended to the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion.
Note: Structure 4Z4X has no ligand bound.
- Include binding site aligned 4TVG and 4TVH.
- Include unaligned 4Z4X.
Fixing a structure allows other entries to be includedthe entry is represented in the Workspace, the circle in the In column is blue without removing the fixed entry from the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
- Toggle on Tile under Workspace Layout in the Workspace Configuration Toolbar.
- Choose Group from the dropdown.
Figure 6-7. Aligned binding sites of proteins without a ligand (pink) and with a ligand (white and green).
Note: Notice the differences in the binding site area for the two aligned PDB files 4TVG and 4TVH with a ligand and the 4Z4X PDB file without a ligand.
- Toggle off Tile by to return to the default Workspacethe 3D display area in the center of the main window, where molecular structures are displayed view.
7. Introducing the Ligand Designer
After superimposing two molecules, their structures can be further explored by making small adjustments to the rotatable groups of one ligand, or modifying its chemical structure. In this section, we will evaluate chemical modifications to a protein-bound ligand.
7.1 Modify a bound ligand with Ligand Designer
- Includethe entry is represented in the Workspace, the circle in the In column is blue only LigandMCMM in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
-
Go to Tasks > Browse > Lead Optimization > Ligand Designer
- The Ligand Designer panel opens.
-
Click Analyze Workspace.
- New entries are added to the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion in the Ligand Designer group.
- The Workspacethe 3D display area in the center of the main window, where molecular structures are displayed now has just a single ligand and a cloud surrounding it to represent the growth space.
Note: You can uncheck Adjust view and style when analyzing to retain the view that you currently have when working in the Ligand Designer.
The darker blue in the growth space is the solvent exposed region.
- Under Display, select 2D/3D Editing.
Note: You can make edits either directly in the sketcher or in the Workspace using the 3D Builder. Any change you make in the Workspace with the 3D builder will be mirrored in the 2D sketcher.
- Change the lower hydroxyl group to a fluorine.
Optional: View Ligand-Receptor Interactions.
The properties under the sketcher are synced with the sketcher and will update automatically before your compound is docked.
-
Click Predict Pose.
- A new entry is added to the Entry Lista simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion.
- Include user_designed_ligand_1 and RAL 600 in the Workspacethe 3D display area in the center of the main window, where molecular structures are displayed.
Note: The modification is not predicted to affect the pose of the ligand in the binding pocket.
8. Conclusion and References
In this tutorial, we have used Maestro to perform many techniques used by chemists for idea generation and lead optimization. Beginning with copying and creating molecules, we drew molecules in 2D and 3D, then explored the conformational space of a ligand. Several different methods of structure alignment for small molecules, ligands bound to proteins, and proteins were explored. Finally, ligands were further analyzed for lead optimization by redocking a modified ligand using Ligand Designer.
For further reading:
9. Glossary of Terms
Entry List - a simplified view of the Project Table that allows you to perform basic operations such as selection and inclusion
included - the entry is represented in the Workspace, the circle in the In column is blue
Project Table - displays the contents of a project and is also an interface for performing operations on selected entries, viewing properties, and organizing structures and data
Scratch Project - a temporary project in which work is not saved, closing a scratch project removes all current work and begins a new scratch project
selected - (1) the atoms are chosen in the Workspace. These atoms are referred to as "the selection" or "the atom selection". Workspace operations are performed on the selected atoms. (2) The entry is chosen in the Entry List (and Project Table) and the row for the entry is highlighted. Project operations are performed on all selected entries
Working Directory - the location that files are saved
Workspace - the 3D display area in the center of the main window, where molecular structures are displayed