Protein Isoelectric Point (pI) Calculator

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Protein Isoelectric Point (pI)

Calculate the isoelectric point (pI) of a protein sequence. pI is the pH at which the protein has no net charge.

Input Type *

Significant Figures

Protein Sequence (1-letter code) *

Valid amino acid codes: A, R, N, D, C, E, Q, G, H, I, L, K, M, F, P, S, T, W, Y, V

pKa Set

Show Details

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Isoelectric Point (pI)

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Isoelectric Point

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Sequence Length

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Net Charge at pH 7

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elementary charge

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Protein Type

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Classification

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Charge vs pH

Net charge of the protein at different pH values

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Chargeable Amino Acid Composition

Count of charged and chargeable residues

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Charge Details

Detailed charge at pH values

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Calculation Details

Step-by-step pI calculation

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pI Tips

Understanding isoelectric point

🧬 Biological Disclaimer: This calculator provides estimates for educational purposes. Actual pI may vary due to protein modifications and environmental conditions.