WarPP

WarPP places water molecules within protein active sites parsed from PDB files to model water-mediated interactions relevant for ligand binding.

Key Features:

• PDB input: Places water molecules using atomic coordinates from PDB files of protein–ligand complexes.
• Interaction geometries: Utilizes interaction geometries derived from comprehensive analysis of protein crystal structures to guide placement.
• Free interaction directions: Generates positions that focus on free interaction directions such as lone pairs of acceptors and hydrogen atoms of donors.
• Active site definition: Computes active sites as a 6.5 Å radius around each atom of any small molecule present in the PDB structure.
• Systematic placement: Generates potential water positions and systematically places water molecules according to the derived interaction geometries.
• Validation dataset: Validated on nearly 1,500 protein–ligand complexes containing almost 20,000 crystallographically observed water molecules.
• Placement accuracy: Achieved correct placement for 80% of crystallographic water molecules within 1.0 Å of their experimental positions in the validation set.
• Computational efficiency: Employs an optimized computational approach to place waters with reduced resource requirements relative to more resource-intensive methods.

Scientific Applications:

• Ligand binding modeling: Improves modeling of water-mediated protein–ligand interactions in structural analyses.
• Structure-based drug design: Supports incorporation of water molecules into drug design workflows to better predict binding interactions.
• Biochemical research: Enables more accurate structural models for studies of enzymatic active sites and molecular recognition.
• Benchmarking and validation: Provides a validated method for comparing predicted water positions against crystallographic data.

Methodology:

Derives interaction geometries from analysis of protein crystal structures; generates potential water positions focused on free interaction directions (lone pairs of acceptors, hydrogen atoms of donors); computes active sites as a 6.5 Å radius around each atom of any small molecule in the PDB; and systematically places water molecules according to the derived interaction geometries.