Properties of the leak permeability induced by a cytotoxic protein from Pseudomonas aeruginosa (PACT) in rat erythrocytes and black lipid membranes

Analysis of the Large Aqueous Pores Produced by a Bacillus Turingiensis Protein Insecticide in Manduca Sexta Midgut‐Brush‐Border‐Membrane Vesicles

“…Instead, if no significant difference is observed between re-swelling traces for two solutes in the presence of toxin, it follows that these are effectively excluded from the toxin-induced pore and this may help delineate the pore size. The same principle underlies the cell lysis protection assay (Weiner et al, 1985) and the liposome swelling assay (Yoshihara et al, 1988) used to size other pore forming agents. At a time point when the sucrose recovery signal reached a maximum level the relative signal recoveries for the test solutes were calculated.…”

Biophysical analysis of novel transport pathways induced in red blood cell membranes

“…In most cases the biophysical characterization of the cytotoxin effect has been tested on model membrane systems with special emphasis on ionic conductances. Recently, however, Weiner et al (1985) have used rat erythrocytes, in parallel with black lipid membranes, to investigate the mode of action of a cytotoxin derived from the pathogenic microorganism Pseudomonas aeruginosa (PACT). They obtained data, measuring the rates of PACT-induced hemolysis in isotonic media consisting of different solutes, consistent with the appearance of hydrophilic pores of an apparent radius equal to or larger than 1.2 nm.…”

“…These treatments include the action of an applied electrical field (Schwister & Deuticke, 1985), oxidation in the pres-ence of diamide (Deuticke et al, 1983), addition of certain toxins (Weiner et al, 1985), or of products formed when the red cell is infected by the malaria parasite (Ginsburg et al, , 1985. Sufficient permeability data are now available to make a detailed investigation of the nature of these induced pathways worthwhile.…”

“…All of the pathways are present in parallel with the pathway of simple diffusion that Lieb and Stein analyzed and the specific pathways present in native erythrocyte membranes . It has been suggested that these parallel, induced pathways are "pores" or "channels" of some kind (Deuticke et al, 1983;Schwister & Deuticke, 1985;Weiner et al, 1985). In this review, we attempt a biophysical analysis of the four pathways just mentioned.…”

Purification and Characterization of Procytotoxin of Pseudomonas aeruginosa

“…CTX has been considered a channel-forming toxin, generating a pore of 2 nm in diameter (8,9). Although morphological identification has yet to be made, we recently found that CTX forms an oligomer on the target membrane (10).…”