The amino acid masses*
| 1-letter code | 3-letter code | Chemical formula | Monoisotopic | Average |
|---|---|---|---|---|
| A | Ala | C3H5ON | 71.03711 | 71.0788 |
| R | Arg | C6H12ON4 | 156.10111 | 156.1875 |
| N | Asn | C4H6O2N2 | 114.04293 | 114.1038 |
| D | Asp | C4H5O3N | 115.02694 | 115.0886 |
| C | Cys | C3H5ONS | 103.00919 | 103.1388 |
| E | Glu | C5H7O3N | 129.04259 | 129.1155 |
| Q | Gln | C5H8O2N2 | 128.05858 | 128.1307 |
| G | Gly | 57.02146 | 57.0519 | |
| H | His | C6H7ON3 | 137.05891 | 137.1411 |
| I | Ile | C6H11ON | 113.08406 | 113.1594 |
| L | Leu | C6H11ON | 113.08406 | 113.1594 |
| K | Lys | C6H12ON2 | 128.09496 | 128.1741 |
| M | Met | C5H9ONS | 131.04049 | 131.1926 |
| F | Phe | C9H9ON | 147.06841 | 147.1766 |
| P | Pro | C5H7ON | 97.05276 | 97.1167 |
| S | Ser | C3H5O2N | 87.03203 | 87.0782 |
| T | Thr | C4H7O2N | 101.04768 | 101.1051 |
| W | Trp | C11H10ON2 | 186.07931 | 186.2132 |
| Y | Tyr | C9H9O2N | 163.06333 | 163.1760 |
| V | Val | C5H9ON | 99.06841 | 99.1326 |