One of the most overlooked yet critical steps in molecular docking is the preparation of proteins for simulations. Poorly prepared systems can lead to inaccurate docking results, wasted computational resources, and misleading conclusions. Thankfully, SAMSON makes this task more accessible with a streamlined workflow that simplifies protein preparation using the Hex Extension.
Why Protein Preparation Matters
Protein preparation is a crucial step because experimental protein structures often include elements that interfere with docking calculations. For instance, water molecules, alternate atomic positions, and monatomic ions can introduce artifacts in the results. Additionally, the absence of hydrogens or incomplete chemical structures can make the docking calculations less reliable.
Streamlining Preparation with SAMSON
SAMSON provides a comprehensive Home > Prepare tool that enables you to tackle common preparation issues quickly and efficiently. Here’s how to get started:
Key Steps in Preparation
- Remove atoms with alternate locations.
- Remove water, monatomic ions, and ligands if present.
- Add hydrogens, ensuring consistency with pre-existing protonation states.
All of these preparatory steps can be accomplished in one go using the preparation dialog in SAMSON. Simply check the relevant options and let SAMSON handle the rest.
Handling Missing Residues and Atoms
If your protein structure has missing residues, heavy atoms, or requires specific pH adjustments, SAMSON users can integrate the PDBFixer extension. This extension allows for fixes like re-building missing residues, as well as adding hydrogens for specific pH conditions. With just a few clicks, you can generate a complete, simulation-ready system.
Note
In this specific tutorial, the system provided in the sample file already has water removed and hydrogens added, ensuring minimal preparation time for users who follow along.
Enhanced Visualization Techniques
Once your protein is prepared, visualization becomes an essential part of quality control. Within SAMSON:
- Select a protein’s structural model in the Document view.
- Navigate to Visualization > Visual model > Ribbons to add secondary structure representations.
You can toggle the visibility of atomistic representations to declutter your workspace and focus on specific features. For further customization and deeper understanding of visual models, check out SAMSON’s interactive tutorials under Help > Tutorials, or refer to the User Guide: Visualizing.
Pro Tip
Shortcut enthusiasts can access the Document view with Ctrl/Cmd + 1. This allows for seamless toggling and visualization of your prepared proteins.
What’s Next?
Once your protein system is prepped, you’ll be ready to move forward with docking simulations in Hex. By starting with a clean, well-prepared structure, you’ll achieve more accurate results, reduce simulation errors, and save time.
To learn more about protein preparation for docking and beyond, refer to the complete tutorial here.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Download SAMSON now at SAMSON Connect.