Open AccessCytK toxin of Bacillus cereus forms pores in planar lipid bilayers and is cytotoxic to intestinal epithelia
Author(s) -
Hardy Simon P,
Lund Terje,
Granum Per Einar
Publication year - 2001
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2001.tb10581.x
Subject(s) - bacillus cereus , toxin , cytotoxic t cell , microbiology and biotechnology , microbial toxins , chemistry , bacillaceae , bacillales , bacteria , biology , biochemistry , bacillus subtilis , in vitro , genetics
CytK is a cytotoxin isolated from a strain of Bacillus cereus cultured from cases of necrotic enteritis and the amino acid sequence of the protein suggests that it may belong to the family of β‐barrel pore‐forming toxins. We show here in planar lipid bilayers the toxin is able to form pores which are weakly anion selective and exhibit an open channel probability close to one. The predicted minimum pore diameter is approximately 7 Å. We also show that cytK is a potent cytotoxin against human intestinal Caco‐2 epithelia. CytK, like other β‐barrel pore‐forming toxins, spontaneously forms oligomers which are resistant to sodium dodecyl sulphate (SDS), but not to boiling. CytK represents a pore‐forming toxin linked with human cases of necrotic enteritis.