Amino Acid Codes
Standard Nomenclature & Reference Guide
Standard 20 Amino Acid Code Reference Chart
The table below provides standard IUPAC abbreviations, molecular weights, and biochemical characteristics for the 20 primary proteinogenic amino acids used in rPeptide peptide synthesis and sequencing.
| Amino Acid | 3-Letter Code | 1-Letter Code | Mol. Wt. (Da) | Properties |
|---|---|---|---|---|
| Alanine | Ala | A | 89.09 | Aliphatic, hydrophobic |
| Arginine | Arg | R | 174.20 | Basic, positively charged |
| Asparagine | Asn | N | 132.12 | Polar, uncharged |
| Aspartic Acid | Asp | D | 133.10 | Acidic, negatively charged |
| Cysteine | Cys | C | 121.16 | Thiol, disulfide bonds |
| Glutamic Acid | Glu | E | 147.13 | Acidic, negatively charged |
| Glutamine | Gln | Q | 146.15 | Polar, uncharged |
| Glycine | Gly | G | 75.07 | Small, non-polar |
| Histidine | His | H | 155.16 | Basic, aromatic |
| Isoleucine | Ile | I | 131.18 | Aliphatic, hydrophobic |
| Leucine | Leu | L | 131.18 | Aliphatic, hydrophobic |
| Lysine | Lys | K | 146.19 | Basic, positively charged |
| Methionine | Met | M | 149.21 | Hydrophobic, thioether |
| Phenylalanine | Phe | F | 165.19 | Aromatic, hydrophobic |
| Proline | Pro | P | 115.13 | Cyclic, conformational rigid |
| Serine | Ser | S | 105.09 | Polar, hydroxylated |
| Threonine | Thr | T | 119.12 | Polar, hydroxylated |
| Tryptophan | Trp | W | 204.23 | Aromatic, indole |
| Tyrosine | Tyr | Y | 181.19 | Aromatic, phenolic |
| Valine | Val | V | 117.15 | Aliphatic, hydrophobic |