Compute pI MW

Compute pI MW computes theoretical isoelectric point (pI) and molecular weight (Mw) from amino acid sequences, accepting UniProt Knowledgebase entries (Swiss-Prot and TrEMBL) or user-provided sequences to support protein characterization and downstream techniques such as two-dimensional gel electrophoresis.

Key Features:

• Theoretical prediction: Calculates pI and Mw directly from amino acid sequences.
• Database compatibility: Accepts UniProt Knowledgebase entries, including Swiss-Prot and TrEMBL.
• User input flexibility: Processes user-provided amino acid sequences for custom analyses.
• Validation: Predictions have been compared against experimentally determined pI values for polypeptides and show good agreement.

Scientific Applications:

• Protein characterization: Provides theoretical pI and Mw for assessing protein properties and interactions.
• Two-dimensional gel electrophoresis (2D-GE): Predicts protein focusing positions within narrow-range immobilized pH gradients under denaturing conditions to inform 2D-GE analysis.
• Structural biology: Assists placement of proteins with known structures on two-dimensional gels by supplying predicted pI and Mw.

Methodology:

Computes pI and Mw by analyzing amino acid sequences under denaturing conditions and compares calculated pI values to experimental measurements for validation.