Table 1.

Biological activity, binding constants, and I_sc of wild-type and mutant toxins toward gypsy moth

Toxin	Neonates LC50,* ng/cm2	Relative potency†	Fourth instar larva ID50,‡ ng/larvae	Relative potency§	Kcom,¶ nM	Bmax,‖ pmol	Isc,** μA/min per cm2
CryIAb	290  (210–350)	1.00	2605  (2000–3050)	1.00	9.3  ±  0.81	8.3  ±  0.9	−4.4  ±  1.2
CryIAa	28  (20–33)	10.36	151  (100–190)	17.25	1.9  ±  0.57	10.3  ±  1.1	−27.3  ±  1.1
N372A	34  (28–41)	8.53	271  (190–301)	9.61	2.1  ±  0.25	11.9  ±  1.3	−24.2  ±  0.9
N372G	35  (27–43)	8.28	274  (210–305)	9.51	2.3  ±  0.30	11.2  ±  0.9	−23.9  ±  1.8
DF-1	8  (6–11)	36.25	149  (91–189)	17.48	0.5  ±  0.08	16.9  ±  1.9	−32.2  ±  1.0
D3	>6000‡‡	>0.05	>10,000‡‡	>0.03	UD	UD	UD

UD, undetectable. 

^*LC₅₀, 50% lethal concentration. Confidence intervals (95%) are given in parentheses. 

^†Relative potency, wild-type (CryIAb) LC₅₀/mutant LC₅₀. 

^‡ID₅₀, dose of toxins that cause growth inhibition in 50% of larvae assayed. Confidence intervals (95%) are in parentheses. 

^§Relative potency, wild-type (CryIAb) ID₅₀/mutant ID₅₀. 

^¶K_com, dissociation constant (determined from homologous competition binding). Each value is the mean ± SD of three experiments. 

^‖B_max, binding site concentration (determined from homologous competition binding). Each value is the mean ± SD of three experiments. 

^**I_sc, Inhibition of short circuit current. Each value is the mean ± SD of three experiments. 

^‡‡Insufficient mortality to calculate IC₅₀ or ID₅₀.