Effects of Bacillus thuringiensis delta-endotoxin on the permeability of brush border membrane vesicles from tobacco hornworm (Manduca sexta) midgut.
1. The effect of two recombinant Bacillus thuringiensis delta-endotoxins on brush border membrane vesicles of Manduca sexta midgut was investigated using an in vitro assay system, based on ion-amino acid cotransport. 2. A CryIA(b)-toxin provoked an increase in the permeability of the vesicles. 3. A CryIB-toxin, not toxic to M. sexta larvae in vivo, had no effect in our assay. 4. In contrast to earlier reports, the increase in permeability was found to be neither selective for K+ nor specifically inhibited by Ca2+ or Ba2+. 5. Our data support the hypothesis that B. thuringiensis delta-endotoxins create non-specific pores.
Hendrickx
K
K
Zoological Institute, Leuven, Belgium.
De Loof
A
A
Van Mellaert
H
H
D000409:Alanine / Q000493:pharmacokinetics; D000818:Animals; D001413:Bacillus thuringiensis / Q000378:metabolism; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D001464:Barium / Q000494:pharmacology; D002021:Buffers; D002118:Calcium / Q000494:pharmacology; D004064:Digestive System / Q000187:drug effects / Q000648:ultrastructure*; D004068:Digestive System Physiological Phenomena; D004731:Endotoxins / Q000494:pharmacology*; D006460:Hemolysin Proteins; D007448:Invertebrates / Q000502:physiology*; D008566:Membranes / Q000187:drug effects / Q000502:physiology; D008871:Microvilli / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D010539:Permeability / Q000187:drug effects; D011188:Potassium / Q000493:pharmacokinetics; D012964:Sodium / Q000493:pharmacokinetics; D013861:Thiocyanates / Q000494:pharmacology; D014316:Tritium
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D002021:Buffers; D004731:Endotoxins; D006460:Hemolysin Proteins; D013861:Thiocyanates; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D014316:Tritium; D001464:Barium; D012964:Sodium; D000409:Alanine; D011188:Potassium; D002118:Calcium; C009941:potassium thiocyanate