Barium and calcium block Bacillus thuringiensis subspecies Kurstaki delta-endotoxin inhibition of potassium current across isolated midgut of larval Manduca sexta.
نویسندگان
چکیده
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.
منابع مشابه
Bacillus thuringiensis delta-endotoxin and larval Manduca sexta midgut brush-border membrane vesicles act synergistically to cause very large increases in the conductance of planar lipid bilayers.
Brush-border membrane vesicles prepared from midguts of Manduca sexta larvae were incorporated into planar phospholipid bilayers. Addition of Bacillus thuringiensis delta-endotoxin to the buffered salt solutions bathing these bilayers resulted in large irreversible increases in conductance. At pH 9.6, the smallest toxin-dependent increase in bilayer conductance observed was 13 nS. Similar condu...
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After incubation at pH 10 or higher, Bacillus thuringiensis spores and endotoxin, at concentrations above 0.1 IU/ml, affected transport parameters in the isolated midgut of Manduca sexta larvae. (Toxic activity was lost during roughly 1 week at pH 11.) About 60% of the short-circuit current was inhibited, and the remainder was reversibly inhibited by anoxia. Electrical resistance was reduced by...
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ورودعنوان ژورنال:
- The Journal of experimental biology
دوره 137 شماره
صفحات -
تاریخ انتشار 1988