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Membrane interactions and surface hydrophobicity of Bacillus thuringiensis δ‐endotoxin CryIC
Author(s) -
Butko Peter,
Cournoyer Micheline,
Pusztai-Carey Marianne,
Surewicz Witold K.
Publication year - 1994
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 - 10.1016/0014-5793(94)80178-9
Subject(s) - bacillus thuringiensis , chemistry , membrane , phospholipid , vesicle , toxin , biophysics , biochemistry , bacteria , biology , genetics
The interaction between Bacillus thuringiensis insecticidal 5‐endotoxin CryIC and phospholipid vesicles was studied by fluorescence spectroscopy. The toxin dissipates the diffusion potential across vesicular membranes, presumably by creating ion permeable channels or pores. This effect is pH‐dependent and strongly increases under acidic conditions. The enhanced membrane‐perturbing activity of CryIC at low pH correlates with the increased surface hydrophobicity of the toxin molecule. The membrane permeabilizing effect of the toxin is further increased by the presence of acidic phospholipids. These findings are discussed in relation to the mode of insecticidal action of the toxin.