FreeSASA

FreeSASA calculates solvent accessible surface areas (SASA) of protein molecules to quantify exposed surface for analyses of protein interactions, stability, and related structural biology studies.

Key Features:

• SASA calculation methods: Implements Lee and Richards and Shrake and Rupley approximations for solvent accessible surface area computation.
• Configurability: Allows tailoring of molecular parameters, accuracy levels, and output granularity for specific analyses.
• Performance and stability: Provides efficiency and numerical stability comparable to or exceeding closed-source legacy SASA programs.
• Implementation: Relies solely on standard C libraries.

Scientific Applications:

• Protein interaction and stability analysis: Quantifies exposed surface areas to inform protein-protein interaction and stability studies.
• Protein–ligand interaction studies: Characterizes solvent exposure of binding sites to assist analysis of binding interfaces and affinities.
• Drug design: Supplies SASA metrics to guide assessment of ligandability and small-molecule design.
• Molecular dynamics simulations: Analyzes SASA over trajectories to monitor conformational changes and solvation dynamics.
• Structural biology analyses: Evaluates surface properties and interface composition in structural investigations.

Methodology:

Computes solvent-accessible surface areas using the Lee and Richards and the Shrake and Rupley approximations, implemented in C using only standard C libraries.