title: Crossing three membranes. Channel formation by aerolysin.
abstract: Aerolysin is a channel-forming toxin responsible for the pathogenicity of Aeromonas hydrophila. It crosses the inner and outer membranes of the bacteria in separate steps and is released as a 52-kDa inactive protoxin which is activated by proteolytic removal of approximately 40 amino acids from the C terminus. The toxin binds to the erythrocyte transmembrane protein glycophorin and oligomerizes before inserting into the membrane, producing a voltage gated, anion selective channel about 1 nm in diameter. Remarkably, proaerolysin appears to be dimeric, whereas the oligomer is a heptamer. Using chemical modification and site-directed mutagenesis, we have identified some of the regions of the molecule which appear to be involved in secretion and in channel formation.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, B.C., Canada.
authors.forename: J T
authors.initials: JT
authors.lastname: Buckley
mesh_terms: D001427:Bacterial Toxins / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects*; D007473:Ion Channels; D052899:Pore Forming Cytotoxic Proteins
chemical_list: D001427:Bacterial Toxins; D007473:Ion Channels; D052899:Pore Forming Cytotoxic Proteins; C032676:aerolysin