title: CytK toxin of Bacillus cereus forms pores in planar lipid bilayers and is cytotoxic to intestinal epithelia.
abstract: 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 beta-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 A. We also show that cytK is a potent cytotoxin against human intestinal Caco-2 epithelia. CytK, like other beta-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.
authors: School of Pharmacy and Biomolecular Sciences, University of Brighton, East Sussex, UK. s.hardy@bton.ac.uk
authors: S P
authors: SP
authors: Hardy
authors: T
authors: T
authors: Lund
authors: P E
authors: PE
authors: Granum
mesh_terms: D016863:Bacillaceae Infections / Q000382:microbiology / Q000503:physiopathology*; D001409:Bacillus cereus / Q000378:metabolism*; D001427:Bacterial Toxins / Q000378:metabolism / Q000633:toxicity; D018938:Caco-2 Cells / Q000473:pathology*; D003603:Cytotoxins / Q000378:metabolism / Q000633:toxicity*; D004768:Enterotoxins / Q000378:metabolism / Q000633:toxicity; D006801:Humans; D007473:Ion Channels / Q000502:physiology; D008051:Lipid Bilayers
chemical_list: D001427:Bacterial Toxins; D003603:Cytotoxins; D004768:Enterotoxins; D007473:Ion Channels; D008051:Lipid Bilayers