Peptide Sequence Analyzer
Advanced peptide sequence analysis: molecular weight, isoelectric point, net charge, hydrophobicity, half-life estimate, modification suggestions, and visual residue mapping with color-coded properties.
Amino Acid Properties Reference
| AA | MW (Da) | pKa | KD |
|---|---|---|---|
| G | 75.03 | — | −0.4 |
| A | 89.09 | — | 1.8 |
| V | 117.15 | — | 4.2 |
| L | 131.17 | — | 3.8 |
| I | 131.17 | — | 4.5 |
| P | 115.13 | — | −1.6 |
| F | 165.19 | — | 2.8 |
| W | 204.23 | — | −0.9 |
| M | 149.21 | — | 1.9 |
| S | 105.09 | — | −0.8 |
| T | 119.12 | — | −0.7 |
| C | 121.16 | 8.18 | 2.5 |
| Y | 181.19 | 10.07 | −1.3 |
| H | 155.16 | 6.00 | −3.2 |
| D | 133.10 | 3.65 | −3.5 |
| E | 147.13 | 4.25 | −3.5 |
| N | 132.12 | — | −3.5 |
| Q | 146.15 | — | −3.5 |
| K | 146.19 | 10.53 | −3.9 |
| R | 174.20 | 12.48 | −4.5 |
Frequently Asked Questions
What is a peptide sequence analyzer?
A peptide sequence analyzer is a computational tool that analyzes amino acid sequences to predict physicochemical properties (molecular weight, pI, charge, hydrophobicity), stability characteristics (half-life, protease susceptibility), and suggests chemical modifications to improve drug-like properties.
How is peptide half-life estimated?
In vivo half-life is estimated using empirical rules based on: (1) N-terminal residue identity (Gln/Asp cyclize rapidly; Pro/Ala/Val stabilize), (2) peptide length (shorter peptides are degraded faster), (3) charge distribution, (4) hydrophobicity, and (5) known protease cleavage motifs.
What modifications can improve peptide stability?
Common modifications include: (1) N-terminal acetylation or amidation, (2) D-amino acid substitution at protease-sensitive sites, (3) PEGylation for extended half-life, (4) cyclization to reduce conformational flexibility, (5) N-methylation at backbone amides, (6) lipidation for albumin binding.
What do the color-coded residues represent?
The color coding indicates amino acid properties: green = hydrophobic, blue = basic/positive, red = acidic/negative, yellow = polar uncharged, orange = special (Pro, Gly, Cys). This helps visualize charge distribution, hydrophobicity patterns, and potential modification sites.