Length
0 residues
Sequence builder
Custom Peptide Builder
Build a peptide sequence from amino acids and view sequence-derived properties such as length, approximate mass, residue composition, and hydrophobicity.
Builder controls
Add residues by search, pick from the amino-acid palette, or paste exact 3-letter tokens and 1-letter codes. Unsupported codes are flagged rather than guessed.
Accepts exact 3-letter amino-acid codes separated by spaces, commas, slashes, or hyphens, or a continuous 1-letter sequence.
Current sequence
0 residuesStart by adding amino acids to build a custom peptide sequence.
Live sequence
The sequence display updates from the currently selected canonical amino acids only.
Add residues to render the sequence chain.
Sequence strings
3-letter format
No residues selected
1-letter format
No residues selected
Computed summary
These values are derived directly from the selected residues and the amino-acid metadata file. Mass is shown as an approximate peptide mass using stored residue masses plus water.
Approximate peptide mass
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Net simplified charge
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Average hydrophobicity
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Class counts
hydrophobic
0
polar
0
acidic
0
basic
0
aromatic
0
special
0
Charge counts
Positive residues
0
Negative residues
0
Neutral residues
0
Residue frequencies
Add residues to see a frequency breakdown.
Total hydrophobicity
Add residues to compute
Residue breakdown
Each row is generated from the selected residues and the current amino-acid dataset. Structure-related columns below are residue-level metadata only.
| Pos. | 3-letter | 1-letter | Name | Class | Charge | Residue mass | Hydrophobicity | Side-chain formula | Side-chain pKa |
|---|---|---|---|---|---|---|---|---|---|
| Add residues to populate the breakdown table. | |||||||||