Table 3.
Sweetness data at 300 ppm20 and calculated binding energies (kcals/mol) of various steviol glycosides at the closed venus fly trap domain 2 (cVFD2), transmembrane domain 2 (TMD2), TMD3, and open VFD3
| Ligand | Sweetness at 300 ppm | Ucav E (kal/mol) | BE order | |||
|---|---|---|---|---|---|---|
| cVFD2 | TMD2 | TMD3 | oVFD3 | |||
| Reb1-5 | 7.40 | –156.96 | –102.72 | –26.20 | –38.83 | VFD2>TMD2>VFD3>TMD3 |
| RebM | 6.55 | –135.74 | –89.80 | –34.23 | –7.09 | VFD2>TMD2>TMD3>VFD3 |
| RebD | 6.15 | –123.85 | –70.85 | –47.90 | –86.27 | VFD2>VFD3>TMD2>TMD3 |
| isoRebM | 6.01 | –119.92 | –79.40 | –40.36 | –48.98 | VFD2>TMD2>VFD3>TMD3 |
| RebA | 5.90 | –104.15 | –70.92 | –85.19 | –82.31 | VFD2>TMD3>VFD3>TMD2 |
| RebB | 5.20 | –72.84 | –96.11 | –98.53 | –24.48 | TMD3>TMD2>VFD2>VFD3 |
| Rubu | 3.87 | –64.66 | –52.21 | –61.30 | –82.41 | VFD3>VFD2>TMD3>TMD2 |
| Reb1-2 | 3.13 | –178.39 | –102.69 | –57.41 | –38.29 | VFD2>TMD2>TMD3>VFD3 |
| RebC | 2.64 | –101.22 | –97.15 | –77.10 | –52.18 | VFD2>TMD2>TMD3>VFD3 |
| hydRebM | 1.14 | –125.02 | –91.55 | –42.71 | –44.69 | VFD2>TMD2>VFD3>TMD3 |
| Ligand | C20 at TMD3 | Ucav E (kal/mol) | BE order | |||
| VFD2 | TMD2 | TMD3 | oVFD3 | |||
| RebM | –125.44 | –86.23 | –17.96 | –102.80 | VFD2>VFD3>TMD2>TMD3 | |
| RebD | –98.10 | –80.84 | –74.23 | –70.02 | VFD2>TMD2>TMD3>VFD3 | |
| Rubu | –84.77 | –61.66 | –39.08 | –42.10 | VFD2>TMD2>VFD3>TMD3 | |
| RebC | –94.57 | –79.47 | –75.47 | –40.81 | VFD2>TMD2>TMD3>VFD3 | |
| Ligand | C20 at TMD2 | Ucav E (kal/mol) | BE order | |||
| VFD2 | TMD2 | TMD3 | oVFD3 | |||
| RebM | –98.37 | –52.10 | –64.81 | –95.54 | VFD2>VFD3>TMD3>TMD2 | |
| RebD | –85.13 | –75.83 | –60.62 | –82.11 | VFD2>VFD3>TMD2>TMD3 | |
| Rubu | –43.88 | –69.10 | –50.80 | –75.95 | VFD3>TMD2>TMD3>VFD2 | |
| RebC | –79.54 | –43.27 | –83.24 | –71.82 | TMD3>VFD2>VFD3>TMD2 | |
The binding energy (BE) was ordered unified cavity energy (UCav E), which is the sum of the non-bonding energy in the unified binding site within 5 Å of ligands.