title: Incorporation of protease K into larval insect membrane vesicles does not result in disruption of integrity or function of the pore-forming Bacillus thuringiensis delta-endotoxin.
abstract: Bacillus thuringiensis delta-endotoxins insert into the brush border membranes of insect larval cells to form ion channels. A possible interaction of these toxins with a cytoplasmic component was examined by preloading vesicles from insect larval cells with protease K followed by incubation with toxin. There was no evidence for toxin antigens smaller than the intact toxin in extracts of solubilized vesicles, nor was there an effect of the inclusion of protease K on either of two functional properties, the formation of toxin aggregates or of ion pores. These toxins, physically and functionally, appear to be confined to the membrane.
authors.affiliation: Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA. aaronson@bilbo.bio.purdue.edu
authors.forename: A
authors.initials: A
authors.lastname: Aronson
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000493:pharmacokinetics* / Q000633:toxicity*; D001427:Bacterial Toxins / Q000493:pharmacokinetics* / Q000633:toxicity*; D002462:Cell Membrane / Q000201:enzymology; D019286:Endopeptidase K / Q000378:metabolism*; D004731:Endotoxins / Q000493:pharmacokinetics* / Q000633:toxicity*; D006460:Hemolysin Proteins; D007814:Larva / Q000201:enzymology; D018402:Manduca; D008871:Microvilli / Q000201:enzymology*; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D012710:Serum Albumin, Bovine; D019286:Endopeptidase K