FMAPB2

FMAPB2 computes the osmotic second virial coefficient (B2) of protein–protein interactions using Fast Fourier Transform (FFT)–based evaluation of interaction energy functions.

Key Features:

• FFT-Based Interaction Evaluation: Uses Fast Fourier Transform (FFT) to represent protein interaction energy terms as correlation functions for efficient computation.
• Comprehensive Interaction Energy Modeling: Models steric repulsion, nonpolar attraction using the Lennard-Jones potential, and electrostatic interactions using the Debye–Hückel potential.
• Mayer f-Function Integration: Calculates the osmotic second virial coefficient (B2) by integrating the Mayer f-function over translational and rotational configurational space between two protein molecules.
• Solvent Condition Adaptability: Adjusts a parameter in the energy function to estimate B2 values under varying solvent conditions including salt concentration, pH, and temperature.

Scientific Applications:

• Protein Solubility Prediction: Uses calculated B2 values to evaluate protein solubility under different solvent conditions.
• Protein Crystallization and Aggregation Analysis: Predicts crystallization conditions and aggregation propensity of proteins.
• Liquid–Liquid Phase Separation Studies: Estimates critical temperatures associated with protein liquid–liquid phase separation relevant to cellular compartmentalization and protein aggregation disorders.

Methodology:

FMAPB2 applies Fast Fourier Transform (FFT) to compute correlation functions representing steric, Lennard-Jones, and Debye–Hückel interaction energies, and integrates the Mayer f-function over translational and rotational configurational space of two protein molecules to calculate the osmotic second virial coefficient (B2).