Calculate key physicochemical properties of a protein sequence, including molecular weight, theoretical pI, net charge at a given pH, GRAVY hydropathy score, extinction coefficient, and instability index. Use this tool when characterizing a recombinant protein — the pI guides buffer choice for ion-exchange chromatography, and the GRAVY score predicts solubility and membrane association. The instability index helps assess whether the protein is likely to remain stable in solution during purification and downstream applications.

Calculated Properties

• Molecular Weight: Sum of amino acid residue masses + water
• Theoretical pI: Isoelectric point from ionizable group pKa values
• Charge at pH: Net charge using Henderson-Hasselbalch equation
• GRAVY Score: Grand average of hydropathy (Kyte-Doolittle)
• Extinction Coefficient: Molar absorptivity at 280 nm
• Instability Index: Predicts protein stability in vitro