Table 2.

Predicted versus experimental binding profiles for selected ligands from PSVLS. Lowest positive concentration refers to the lowest concentration tested that gave a positive response. Highest concentration tested refers to the highest concentration tested that gave a negative response. Inhibition results for aminopterin, desmosine, paclitaxel and fructose are from Dadgar et al.[19] and were obtained using FRET for 10 μM of each ligand against BoNT/A LC (10 nM). (+) indicates positive response, whereas (−) indicates negative response in the SPA binding assays.

Compound Name	Computational Binding Preference (score)1	BoNT/A LC	BoNT/A HC	Lowest Positive Concentration	Highest Negative Concentration	EC50	% Inhibition at 10μM[19]
Aminopterin	R27 (−4.7) HC R8 (−4.8) HC R7 (−4.7) HC	−	+	1000 nM4	500nM3	703 nM	11
Desmosine	R6 (−5.5) LC R23 (−4.9) LC R10 (−4.8) HC R1 (−4.8) LC	−	+	2000 nM4	3000 nM3	1.6 μM	25
Solanesol	R6 (−6.0) LC	−	−	NA	300 nM	NA	NA
Solanesyl pyrophosphate	R27 (−13.8) HC R3 (−13.4) HC R7 (−13.4) HC R2 (−12.9) LC R10 (−12.9) HC	+	+	600 nM2	NA	ND	NA
Paclitaxel	R14 (−11.0) LC	+	−	50 nM	50 nM	17 nM	95
Fructose	R17(−1.9) HC	−	−	NA	3000 nM	NA	0

¹Score corresponds to holistic scores [19] at the best region(s) among the 33 regions scanned. Multiple regions are listed if the difference in binding energies was 1 unit or less. Scores not passing the per-region non-binder/binder threshold are shown in grey italic.

²The lowest positive concentration of SolanesylPP was 600 nM for both BoNT/A HC and LC.

³Ligands were tested at higher concentration against BoNT/A LC, producing a negative response; no lower concentrations were tested afterwards.

⁴Positive ligands at higher concentration were tested against BoNT/A HC at two lower concentrations (250 nM and 50 nM), producing negative responses.

NA = not applicable; ND = not determined; LC = light chain, including the catalytic site among others; HC = heavy chain.