Table 1.
The taste qualities of amino acids and sensing mechanisms by G protein-coupled receptors (GPCRs).
| Amino acid | Human taste perception | Sensing mechanism by GPCRs |
|---|---|---|
| ʟ-Alanine | Sweet | GPRC6A |
| ʟ-Arginine | Bitter | GPRC6A |
| ʟ-Asparagine | Bitter | T1R1/T1R3 |
| ʟ-Aspartic acid | Umami, sour | T1R1/T1R3 |
| ʟ-Cysteine | Sulfurous | T1R1/T1R3 |
| ʟ-Glutamic acid | Umami, salty | T1R1/T1R3, mGluRs |
| ʟ-Glycine | Sweet | GPRC6A |
| ʟ-Histidine | Bitter | CaSR |
| ʟ-Hydroxyproline | Sweet | T1R1/T1R3 |
| ʟ-Isoleucine | Bitter | T1R1/T1R3 |
| ʟ-Leucine | Bitter | T1R1/T1R3 |
| ʟ-Lysine | Bitter, salty, sweet | GPRC6A |
| ʟ-Methionine | Bitter, sulfurous | GPRC6A |
| ʟ-Phenylalanine | Bitter | CaSR |
| ʟ-Proline | Sweet | T1R1/T1R3 |
| ʟ-Serine | Sweet | GPRC6A |
| ʟ-Threonine | Sweet | T1R1/T1R3 |
| ʟ-Tryptophane | Bitter | CaSR |
| ʟ-Tyrosine | Bitter | Not detectable yet |
| ʟ-Valine | Bitter | T1R1/T1R3 |