Protein Isoelectric Point Calculator

Calculate pI and net charge from protein sequence

Protein Sequence

Ionizable Residues

Basic (Positive)

Lysine (K)1
Arginine (R)1
Histidine (H)1

Acidic (Negative)

Aspartic (D)2
Glutamic (E)0
Cysteine (C)2
Tyrosine (Y)0

Isoelectric Point (pI)

7.00

Net charge = 0 at this pH

Charge Analysis

Sequence Length41 aa
Total Basic Residues+3
Total Acidic Residues-2
Net Charge (theoretical)+1

Charge at Common pH

pH 7.0+0.00
pH 7.4 (physiological)-0.18

Interpretation

Basic protein - positively charged at physiological pH