Table 4. Binding data of recombinant NlugOBPs with different plant volatiles (Carboxylic acids, Alkanes, Terpenes and Others).
| Ligand | Ligand name | OBP1 | OBP2 | OBP3 | ||||||||
| number | Structural formula | IC50 | Ki | IC50 | Ki | IC50 | Ki | |||||
| (µM) | (µM) | (µM) | (µM) | (µM) | (µM) | |||||||
| Carboxylic acids | ||||||||||||
| 26 | Dodecanoic acid/ C12H24O2 | 12.1 | 10.3 | >50 | >50 | 13.9 | 9.9 | |||||
| 27 * | Palmitic acid/ C16H32O2 | 25.9 | 22.1 | >50 | >50 | 10.1 | 7.2 | |||||
| Alkanes | ||||||||||||
| 28 | Eicosane/C20H42 | >50 | >50 | >50 | >50 | >50 | >50 | |||||
| 29 | Tridecane/C13H28 | >50 | >50 | >50 | >50 | >50 | >50 | |||||
| 30 | Heptadecane/ C17H36 | >50 | >50 | >50 | >50 | >50 | >50 | |||||
| 31 | Octadecane/C18H38 | >50 | >50 | >50 | >50 | >50 | >50 | |||||
| 32 | Tetradecane/ C14H30 | >50 | >50 | >50 | >50 | >50 | >50 | |||||
| Terpenes | ||||||||||||
| 33 * | Myrcene/C10H16 | 19.0 | 16.2 | 33.9 | 29.1 | 10.1 | 7.2 | |||||
| 34 * | (+)-α-Pinene/ C10H16 | 36.4 | 31.1 | >50 | >50 | 16.1 | 11.5 | |||||
| 35 * | (R)-(+)-Limonene/ C10H16 | 32.4 | 27.6 | >50 | >50 | 33.1 | 23.6 | |||||
| 36 | β-Caryophyllene/ C15H24 | >50 | >50 | 30.1 | 25.9 | 37.4 | 26.7 | |||||
| 37 * | β- Ionone/C13H20O | 25.2 | 21.5 | 25.8 | 22.2 | 8.5 | 6.1 | |||||
| 38 | Cumene /C9H12 | >50 | >50 | 39.2 | 33.7 | 37.2 | 26.6 | |||||
| 39 | Methoprene/C19H34O3 | 19.4 | 16.6 | 21.1 | 18.1 | 14.7 | 10.5 | |||||
| Others | ||||||||||||
| 40 | Cineole/C10H18O | >50 | >50 | >50 | >50 | >50 | >50 | |||||
| 41 | 2,6-Di-tert-butylphenol/ C14H22O | 22.3 | 19.0 | >50 | >50 | 13.3 | 9.5 | |||||
*Marked ligands were identified as rice plant volatile according to literatures; “>50” for the IC50 and Ki means that IC50 or Ki cannot be accurately calculated with the ligand concentration range tested in the assay.