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Ion channels formed in planar lipid bilayers by Bacillus thuringiensis toxins in the presence of Manduca sexta midgut receptors
Author(s) -
Schwartz Jean-Louis,
Lu Yiang-Jiang,
Söhnlein Petra,
Brousseau Roland,
Laprade Raynald,
Masson Luke,
Adang Michael J
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)00801-6
Subject(s) - manduca sexta , midgut , ion channel , bacillus thuringiensis , manduca , toxin , receptor , phospholipid , biophysics , biochemistry , membrane , lipid bilayer , biology , chemistry , microbiology and biotechnology , insect , botany , bacteria , genetics , larva
A purified, GPI‐linked receptor complex isolated from Manduca sexta midgut epithelial cells was reconstituted in planar lipid bilayers. CryIAa, CryIAc and CryIC, three Bacillus thuringiensis insecticidal proteins, formed channels at much lower doses (0.33–1.7 nM) than in receptor‐free membranes. The non‐toxic protein CryIB also formed channels, but at doses exceeding 80 nM. The channels of CryIAc, the most potent toxin against M. sexta , rectified the passage of cations. All other toxin channels displayed linear current–voltage relationships. Therefore, reconstituted Cry receptors catalyzed channel formation in phospholipid membranes and, in two cases, were involved in altering their biophysical properties.