ProMoST

ProMoST calculates the impact of single or multiple post-translational modifications (PTMs) on protein molecular weight (MW) and isoelectric point (pI) to support interpretation of two-dimensional (2D) gel electrophoresis patterns.

Key Features:

• MW and pI calculation: Calculates changes in molecular weight and isoelectric point for proteins bearing single or multiple PTMs.
• PTM types modeled: Models phosphorylation, acetylation, deamination, alkylation, cysteine oxidation, and tyrosine nitration.
• Titratable-group modeling: Considers addition, removal, or modification of titratable groups by PTMs that alter pI.
• Theoretical 2D gels: Generates theoretical two-dimensional gel images from calculated pI and MW values.
• Protein-specific pI shifts: Accounts for protein-specific buffering capacities and baseline pIs that can cause identical PTMs to produce different pI shifts.
• Per-protein outputs: Provides calculated MW and pI values for each protein under study.

Scientific Applications:

• Modeling PTM effects on protein properties: Predicts how phosphorylation, acetylation, deamination, alkylation, cysteine oxidation, and tyrosine nitration change protein MW and pI.
• Interpreting 2D gels: Explains and predicts shifts in protein positions on 2D gel electrophoresis arising from PTM-induced pI and MW changes.
• Matching theory to experiment: Enables comparison of theoretical 2D gel patterns with experimental gels to suggest probable PTMs.
• Guiding follow-up studies: Prioritizes candidate modifications for targeted biochemical characterization and investigation of regulatory and signaling roles.

Methodology:

Computationally calculates MW and pI changes induced by specified PTMs including modeling effects on titratable groups, and generates theoretical 2D gel images from the resulting pI and MW values.