Aerolysin of Aeromonas sobria: evidence for formation of ion-permeable channels and comparison with alpha-toxin of Staphylococcus aureus

Chakraborty, Trinad; Schmid, Alex P.; Notermans, S.; Benz, Roland

doi:10.1128/iai.58.7.2127-2132.1990

Cited by 83 publications

(46 citation statements)

References 32 publications

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“…The channel-forming complex is still unstable, possibly because of the interaction of the channel with the N-terminus of HlyA. Unstable haemolysin oligomers are in agreement with other studies, in which, in contrast to aerolysin [22] and a-toxin [23], no indication for stable oligomers has been observed [1]. Aerolysin and a-toxin form stable channels in the presence of lipids with a structure similar to those of the porins [15].…”

Section: Discussionsupporting

confidence: 91%

haemolysin of Escherichia coli: Comparison of pore-forming properties between chromosome and plasmid-encoded haemolysins

Benz

1992

FEMS Microbiology Letters

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Section: Discussionsupporting

confidence: 91%

haemolysin of Escherichia coli: Comparison of pore-forming properties between chromosome and plasmid-encoded haemolysins

Benz

1992

FEMS Microbiology Letters

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“…Channels formed by El Tor hemolysin appear to be very similar to those observed in the presence of aerolysin from Aeromoiias [27,31 I and a-toxin from Stctphylococcus nureus 1301.…”

Section: Discussionmentioning

confidence: 56%

HlyA Hemolysin of Vibrio Cholerae O1 Biotype El Tor

Menzl

Maier

Chakraborty

et al. 1996

European Journal of Biochemistry

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Hemolysin (HlyA) was concentrated from supernatants of different Vibrio cholerue 01 biotype El Tor strains by ammonium sulfate precipitation. The concentration of the toxin in the supernatants and in the precipitates was quantified using its hemolytic activity. The toxin formed a high molecular-mass band (about 220 kDa) on SDS/PAGE while the toxin monomer had a molecular mass of 60 kDa when it was heated. The addition of the El Tor hemolysin oligomers, but not that of the monomers, to the aqueous phase bathing lipid bilayer membranes resulted in the formation of ion-permeable channels, which had long lifetimes at small voltages. The hemolysin channel had a single-channel conductance of 350 pS in 1 M KC1. These results defined hemolysin (HlyA) from V choleme as a channel-forming component with properties similar to other cytolytic toxins. The long lifetime of the channel suggested that the channel-forming oligomer did not show a rapid association/dissociation reaction. At voltages larger than 50 mV, the hemolysin channel was voltage dependent in an asymmetric fashion dependent on the side of its addition. The single-channel conductance of the hemolysin (HlyA) from V cholerue 0 1 biotype El Tor channel was a linear function of the bulk aqueous conductance, which suggested that the toxin forms aqueous channels with an estimated minimum diameter of about 0.7 nm. The hemolysin channel of V cholerue was found to be moderately anion-selective. The pore-forming properties of hemolysin (HlyA) from V cholerue 0 1 biotype El Tor were compared with those of aerolysin of Aeromonus sobriu and atoxin from Staphylococcus uureus. All these cytolytic toxins must probably oligomerize for activity in biological and artificial membranes and form anion-selective channels.Keywords: hemolysin; ion channel; toxin oligomer; lipid bilayer membrane; Vibrio choleru biotype El Tor.The Gram-negative Vibrio cholerue is an intestinal pathogen that is non-invasive and adheres to the apical side of the small intestine [I, 21. The epidemic qualities of this pathogen have recently been dramatically underscore by the reappearance of cholera in the Western Hemisphere after more than 100 years and the emergence of a new strain, the V cholerae 0 -1 39 Bengal strain, that appeared in India and spread rapidly to countries surrounding the Indian Ocean [3]. Virulence factors elaborated by Y cholerae include cholera toxin, colonization factor, toxinco-regulated pilus, zona occuledens toxin and the regulatory elements ToxR, ToxS and ToxT [2].To establish an infection, V cholerue colonizes the intestinal surface and releases cholera toxin composed of two subunits [4, 51. The binding component ( 5 B subunits) binds to the surface and facilitates the entry of the A subunit into the epithelial cells. The A subunit effects an increase of the intracellular level of cyclic AMP. The high level of intracellular AMP stimulates the secretion of chloride and bicarbonate out of the cell and leads to diarrhoea because of the severe loss of isotonic body fluid [I, 21. Chol...

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“…Not only erythrocytes but also cultured cells are sensitive to aerolysin (24,26). Subsequently, the hemolysin from A. sobria strain AB3 (which has been named AEAER) was also reported to form pores in the membrane (4).…”

Section: Discussionmentioning

confidence: 99%

Purification and Characterization of Enterotoxin Produced by Aeromonas sobria

Fujii

Nomura

Kanzawa

et al. 1998

Microbiology and Immunology

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We purified the toxin of Aeromonas sobria capable of inducing a positive response in the mouse intestinal loop assay. The purified toxin showed a positive response not only in the loop assay but also in a hemolytic assay. Subsequently, we cloned the toxin gene and demonstrated that the product of this gene possessed both hemolytic and enterotoxic activities. These results showed that the enterotoxin of A. sobria possesses hemolytic activity. Nucleotide sequence determination of the toxin gene and amino acid sequence analysis of the purified toxin revealed that it is synthesized as a precursor composed of 488 amino acid residues, and that the 24 amino-terminal amino acid residues of the precursor is removed in the mature toxin. As antiserum against the purified toxin neutralized the fluid accumulation induced by living cells not only of A. sobria but also of A. hydrophila, this and antigenically related toxin(s) are thought to play an essential role in the induction of diarrhea by these organisms. The toxin-injured Chinese hamster ovary (CHO) cells induced the release of intracellular lactose dehydrogenase (LDH). The release of LDH from CHO cells and the lysis of erythrocytes by the toxin were repressed by the addition of dextran to the reaction solution, indicating that the toxin forms pores in the membranes and that the cells were injured by the osmotic gradient developed due to pore formation. However, the histopathological examination of intestinal cells exposed to the toxin showed that it caused fluid accumulation in the mouse intestinal loop without causing cellular damage.

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Aerolysin of Aeromonas sobria: evidence for formation of ion-permeable channels and comparison with alpha-toxin of Staphylococcus aureus

Cited by 83 publications

References 32 publications

haemolysin of Escherichia coli: Comparison of pore-forming properties between chromosome and plasmid-encoded haemolysins

haemolysin of Escherichia coli: Comparison of pore-forming properties between chromosome and plasmid-encoded haemolysins

HlyA Hemolysin of Vibrio Cholerae O1 Biotype El Tor

Purification and Characterization of Enterotoxin Produced by Aeromonas sobria

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