Barium and calcium block Bacillus thuringiensis subspecies Kurstaki delta-endotoxin inhibition of potassium current across isolated midgut of larval Manduca sexta.
Ba2+ and Ca2+ prevent and reverse the Btk delta-endotoxin inhibition of the short-circuit current in isolated lepidopteran midgut. These findings support the K+ pump-leak steady-state model for midgut K+ homeostasis and the K+ channel mechanism of Bt toxin action. They provide a new tool with which to study the interactions between Bt toxin and midgut cell membranes.
Crawford
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DN
Department of Biology, Temple University, Philadelphia, PA 19122.
Harvey
W R
WR
D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D001464:Barium / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D004068:Digestive System Physiological Phenomena; D004731:Endotoxins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006460:Hemolysin Proteins; D006706:Homeostasis; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D007814:Larva; D008954:Models, Biological; D009036:Moths; D011188:Potassium / Q000378:metabolism*
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007473:Ion Channels; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D001464:Barium; D011188:Potassium; D002118:Calcium