Anthrax Biosensor, Protective Antigen Ion Channel Asymmetric Blockade
ARMY MEDICAL RESEARCH INST OF INFECTIOUS DISEASES FORT DETRICK MD
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Bacillus anthracis secretes three proteins protective antigen, PA lethal factor, LF and edema factor, EF that are the basis for anthrax infection. We present electrophysiological measurements that demonstrate the effect of full-length LF and EF on ion channels formed by the proteolytically activated species of PA PA63 in planar lipid bilayer membranes. LF and EF convert the heptameric PA63 channel current-voltage relationship from slightly nonlinear to one that is highly rectifying and diode-like at pH 6.6. This striking effect provides an innovative method for characterizing functional toxin interactions and can be applied as an anthrax therapeutic biosensor.
- Medicine and Medical Research