Protein-protein docking is a complex task often requiring careful preparation of molecular systems. Small inconsistencies in systems, such as alternate atom locations, missing hydrogens, or unwanted molecules like water or ligands, can lead to errors or inaccuracies in docking results. The Hex SAMSON Extension simplifies this process by providing an easy way to ensure your protein structures are optimized before running the docking workflow.
Why Proper Protein Preparation Matters
Before running a docking simulation, it’s essential to ensure that your protein receptor and ligand are “cleaned” and protonated correctly to match the docking program’s requirements. Improper structure preparation can result in unreliable results, wasted computational time, or even docking runs that fail altogether. Here is where SAMSON’s Prepare tool can significantly ease this often tedious step, automating many tasks with just a few clicks.
How to Prepare Proteins in Hex
SAMSON comes with a simple workflow for protein preparation, integrated within the Hex Extension:
- Remove alternate atom locations: Proteins obtained from experimental data often include alternate conformations for the same atoms. Removing these avoids ambiguities in docking.
- Remove unnecessary molecules: Water, ions, or other ligands not involved in docking can interfere with results. The tool automatically removes them.
- Protonate your structures: Hydrogens may be missing from input protein structures. Adding them ensures accuracy in calculations, such as energy minimizations and hydrogen bond predictions. Note that if the hydrogens are already present and reflect a specific protonation state, you can preserve them without changes.
This process is straightforward. Simply navigate to Home > Prepare in SAMSON and configure the preparation options as shown in the image below:
If your structure has missing residues or heavy atoms (e.g., incomplete side chains), you can further refine it using the PDBFixer Extension. This extension provides tools to restore missing elements and adjust protonation for specific pH values when needed, ensuring your system is well-prepared for docking.
Prepare Like a Pro
For new users, protein preparation in SAMSON is quite intuitive. The platform not only minimizes errors in input structures but also makes it simple to focus on the actual docking experiment rather than spending excessive time preprocessing files. If you’re using the tutorial system provided with the Hex Extension (featuring proteins 2PTC_E and 2PTC_I), most preparation steps are already completed for you. For your own structures, adopting this workflow is highly recommended for smooth docking runs.
Extra Tips for Visualization
To ensure your system looks organized and comprehensible, consider using Visualization options in SAMSON. You can represent your proteins with ribbons for a clean, secondary structure-based view. This is particularly helpful if you need to verify molecular alignments before proceeding with docking.
Toggle different visual models or structural features via the Document view and Visualization menu for better clarity.
Learn More
Efficient preparation leads to better docking results, providing you with reliable configurations to base further analysis on. Dive deeper into the full workflow by reading the original documentation: official SAMSON Hex Extension guide.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON at SAMSON Connect.