TABLE 3.

Binding characteristics of ¹²⁵I-labeled Cry1 toxins as determined by homologous competition assays using BBMV from whole neonate and third-instar larvae^a

Toxin	Larvae	M. sexta		P. brassicae		M. brassicae		S. exigua
		Kcom (nM)	Bmax (pmol/mg)	Kcom (nM)	Bmax (pmol/mg)	Kcom (nM)	Bmax (pmol/mg)	Kcom (nM)	Bmax (pmol/mg)
Cry1J	Neonateb	80.3 ± 24.6	159 ± 47.3	58 ± 25	94 ± 33			231 ± 109	680 ± 326
	Third instarc	61.3 ± 17.16	109 ± 28	39 ± 10	58 ± 14	NDd	ND	438 ± 96	1,130 ± 287
Cry1Ca	Neonate	7.2 ± 2.6	114 ± 32			2.2 ± 1.9	53 ± 33
	Third instar	7.6 ± 2.3	72 ± 18	ND	ND	3.4 ± 2.3	172 ± 62	ND	ND
Cry1Ac	Neonate	103 ± 45	2,988 ± 1,055	415 ± 113	2,556 ± 860
	Third instar	25 ± 23	211 ± 189	406 ± 361	1,558 ± 1760	ND	ND	ND	ND
Cry1Ba	Neonate	202 ± 85	1,873 ± 812	2.8 ± 2.3,	8.1 ± 5.8,	ND	ND	ND	ND
				424 ± 189e	1,320 ± 608e
	Third instar	105 ± 31.5	738 ± 214	174 ± 46.3	726 ± 207

^aK_com and B_max were calculated from a LIGAND analysis of the binding experiment results. The values are means ± standard errors of the means.

^bBBMV were prepared from whole neonate larvae.

^cBBMV were prepared from whole third-instar larvae.

^dND, not determined.

^eThe first value is the value for a high-affinity binding site, and the second value is the value for a low-affinity binding site.