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Properties of Pseudomonas aeruginosa exotoxin A ionic channel incorporated in planar lipid bilayers
Author(s) -
Gambale F.,
Rauch G.,
Belmonte G.,
Menestrina G.
Publication year - 1992
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(92)80833-3
Subject(s) - exotoxin , pseudomonas aeruginosa , biophysics , chemistry , phospholipid , electrolyte , lipid bilayer , voltage , membrane , toxin , physics , biochemistry , biology , bacteria , electrode , quantum mechanics , genetics
Acidic conditions induce the incorporation of Pseudomonas aeruginosa exotoxin A into phospholipid planar bilayers and the formation of pores permeable to electrolytes. Channel openings occur as single events, although they may occasionally cluster in bursts. In 100 mM KCl, the elementary single channel current amplitude is 3.1 pA (at a transmembrane voltage of 100 mV), the mean open time is 1.3 ms, while bursts may last for several seconds. Noise analysis gave results identical to single channel analysis. Voltage pulse protocols and continuous cycling voltage ramps showed that the toxin channel is voltage dependent, having a higher probability of being open at positive voltages.