LIGAND BLOT IDENTIFICATION OF A MANDUCA-SEXTA MIDGUT BINDING-PROTEIN SPECIFIC TO 3 BACILLUS-THURINGIENSIS CRYIA-TYPE ICPS

The CryIA(a) CryIA(b) and CryIA(c) Bacillus thuringiensis insecticidal crystal proteins (ICPs) were used in ligand-blot experiments to detec t specific binding proteins in brush-border membrane vesicles (BBMV) o f Manduca sexta. We identified a protein which binds these three CryIA -type ICPs. The apparent molecular mass of the protein, estimated on S DS-PAGE, was 210 kDa as was the CryIA(b) binding protein previously de scribed by Vadlamudi and col. We have also demonstrated, in ligand blo t experiments, that CryIA(a) and ClyIA(c) compete with CryIA(b) for bi nding this 210 kDa protein. Properties of the binding molecule can be correlated with knowledge previously aquired through radiolabelled bin ding experiments. (C) 1994 Academic Press, Inc.