Table 1. Binding of pure organic compounds to selected recombinant LstiGOBP2.
Ligands | LstiGOBP2 | Ligands | LstiGOBP2 | ||||
IC50 | Int | Ki | IC50 | Int | Ki | ||
Aliphatic alcohols | Aromatic compounds | ||||||
1-Hexanol | 11 | 42 | 6.5 | Benzaldehyde | 19 | 48 | 11.2 |
Cis-3- hexen-1-ol | 19 | 49 | 11.2 | Cinnamaldehyde | 17 | 45 | 10 |
Cis-2-hexen-1-ol | 24 | 59 | 14.1 | Phenyl acetaldchyde | 20 | 50 | 11.8 |
4-Hexen-1-ol | 26 | 58 | 15.3 | 2,4-Di-tert-butylphenol | 20 | 50 | 11.8 |
1-Heptanol | 10.5 | 40 | 6.2 | Dimethyl phthalate | 36 | 64 | 21.2 |
6-Methyl-5-hepten-2-ol | 28 | 63 | 16.5 | Methyl salicylate | - | 83 | - |
Iso-octanol | 28 | 58 | 16.5 | Terpenoids | |||
Aliphatic aldehydes | α-ionone | 8 | 39 | 4.7 | |||
1-Pentanal | 14 | 46 | 8.2 | β-ionone | 11 | 37 | 6.5 |
1-Hexanal | 12.5 | 36 | 7.3 | Myrcene | 25 | 56 | 14.7 |
Trans-2-hexenal | 10.5 | 50 | 6.2 | Camphene | 23 | 54 | 13..5 |
1-Heptanal | 24 | 52 | 14.1 | Camphor | 14 | 41 | 8.2 |
1-Octanal | 24 | 52 | 14.1 | (-)-Linalool | 28 | 53 | 16.5 |
1-Nonanal | 39 | 66 | 22.9 | Geraniol | 22 | 54 | 12.9 |
Aliphatic ketones | (-)-Trans-caryophyllene | - | 86 | - | |||
6-Methyl-5-hepten-2-one | 28 | 64 | 16.5 | Heterocyclic compound | |||
Aliphatic ester derivatives | Benzothiazole | 22 | 52 | 12.9 | |||
Cis-3-hexenyl acetate | 29 | 57 | 17.1 | Sex pheromone component | |||
Trans-2-hexenyl acetate | 28 | 59 | 16.5 | Trans-11-tetradecen-1-yl acetate | 18 | 48 | 10.6 |
Dimethyl phthalate | 20 | 50 | 11.8 |
Solution of protein was at 2 µM, and the added concentration of 1-NPN was in line with the dissociation constants of LstiGOBP2/1-NPN complex calculated. Then the mixed solution was titrated with 1 mM solution of each ligand in methanol to final concentrations of 2–50 µM. For the protein, we report the fluorescence intensity (Int) measured at the ligand concentration (20 µM) as percent of the initial fluorescence, the concentration of ligand halving the initial fluorescence intensity (IC50), where applicable, and the relative dissociation constant (Ki) calculated as described in “Materials and methods”. Dissociation constants of ligands whose IC50 exceeded 50 mM are represented as “-”. Other potential ligands were tested, but the remaining 17 potential ligands did not bind LstiGOBP2. These compounds included1-Octen-3-ol, Trans-2-hexen-1-ol, R-(+)-Limonene, α-Phellandrene, α-Terpineol, Nerolidol, α-Pinene, Octadecene, Methyl anthranilate, Methyl palmitate, Undecane, Dodecane, Tridecane, Tetradecane, Pentadecane, Hexadecan and Heptadecane.