Immunoblot of Cry1Ac and H168R, following incubation with M. sexta BBMV. (A) Lanes 1 to 3, 20 μg of BBMV incubated with 20, 40, and 60 ng of Cry1Ac toxin, respectively; lane 4, 60 ng of Cry1Ac toxin; lanes 5 to 7, 20 μg of BBMV incubated with 20, 40, and 60 ng of H168R toxin, respectively; lane 8, 60 ng of H168R toxin; lane 9, standards as in Fig. 2 plus ovalbumin (45 kDa) and carbonic anhydrase (29 kDa). (B) Toxin samples (20 ng) were incubated with 20 μg of BBMV and then extracted for different times at 65°C. Lane 1, Cry1Ac toxin extracted at 65°C for 15 min; lane 2, Cry1Ac toxin extracted at 65°C for 5 min; lane 3, 20 ng of Cry1Ac toxin; lane 4, H168R toxin extracted at 65°C for 15 min; lane 5, H168R toxin extracted at 65°C for 5 min; lane 6, 20 ng of H168R toxin. Markers on the right indicate (from top to bottom) positions of myosin, β-galactosidase, and bovine serum albumin.