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Molecular Weight Calculation
Isoelectric Point Prediction
Amino Acid Composition Analysis
Chemical Composition Analysis
Enter Protein Sequence
Calculation Results
Please enter a protein sequence and click the "Calculate Parameters" button
Instructions
Enter Protein Sequence
Enter your protein sequence in the text box using single-letter amino acid codes (e.g., ACDEFGHIKLMNPQRSTVWY). Multiple sequences are supported, each starting with >.
Select Tag (Optional)
You can optionally add a common protein tag to either the N-terminus or C-terminus of your sequence, such as His tag or FLAG tag, to facilitate downstream experimental procedures.
Calculate Parameters
Click the "Calculate Parameters" button to analyze your protein sequence and compute parameters such as molecular weight, isoelectric point, and amino acid composition.
View Results
After calculation, detailed results will be displayed on the right, including molecular weight, theoretical isoelectric point, amino acid composition, and chemical composition.
Video Tutorial
Need help using the tool? This video tutorial will guide you through the full process — from sequence input to result analysis — in just a few minutes.
Calculation Principles
Molecular Weight Calculation
The molecular weight is calculated based on the average molecular weight of each amino acid residue, considering the loss of water molecules during protein synthesis. The formula is:
Protein Molecular Weight = ∑(Molecular Weight of Each Amino Acid) - (n-1) × 18.015
Where n is the number of amino acid residues, and 18.015 is the molecular weight of water.
Isoelectric Point Prediction
The isoelectric point (pI) is the pH at which a protein carries no net electrical charge. This tool uses the Harpaz method to calculate the theoretical pI, considering the pKa values of each ionizable amino acid residue.
Amino Acid Composition Analysis
This analysis calculates the count and percentage of each amino acid in the protein sequence, helping to understand the chemical properties and structural characteristics of the protein.
Chemical Composition Analysis
This analysis calculates the number of various atoms in the protein, including carbon (C), hydrogen (H), nitrogen (N), oxygen (O), sulfur (S), etc., and their percentage composition.
