HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 277, Issue 8, 6143-6152, February 22, 2002

This Article Full Text Full Text (PDF) All Versions of this Article: 277/8/6143    most recent M103939200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Knapp, O. Articles by Popoff, M. R. Search for Related Content PubMed PubMed Citation Articles by Knapp, O. Articles by Popoff, M. R. Social Bookmarking                      What's this?

Interaction of Clostridium perfringens Iota-Toxin with Lipid Bilayer Membranes
DEMONSTRATION OF CHANNEL FORMATION BY THE ACTIVATED BINDING COMPONENT Ib AND CHANNEL BLOCK BY THE ENZYME COMPONENT Ia^*

Oliver Knapp, Roland Benz^§, Maryse Gibert^¶, Jean C. Marvaud^¶, and Michel R. Popoff^¶

From the  Lehrstuhl für Biotechnologie, Theodor-Boveri-Institut (Biozentrum) der Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany and ^¶ Interactions Bactéries Cellules, Institut Pasteur, 28 Rue du Dr Roux, F-75724 Paris cedex 15, France

The interaction between model lipid membranes and the binding component (Ib) of the ADP-ribosylating iota-toxin of Clostridium perfringens was studied in detail. Ib had to be activated by trypsin to result in channel formation in artificial lipid bilayers. The channels formed readily by Ib had a small single-channel conductance of about 85 picosiemens in 1 M KCl. Channel function was blocked in single-channel and multichannel experiments by the enzymatic component Ia in a pH-dependent manner. The strong Ia-mediated channel block of Ib occurred only when the pH was at least lowered to pH 5.6. The single-channel conductance showed a linear dependence on the bulk aqueous KCl concentration, which indicated that the channel properties were more general than specific. Zero current membrane potential measurements suggested the Ib channel has an ~6-fold higher permeability for potassium ions than for chloride. The selectivity ratio changed for salts composed of cations and anions of different mobility in the aqueous phase, again suggesting that Ib formed a water-filled general diffusion pore. Asymmetric addition of activated Ib to lipid bilayer membranes resulted in an asymmetric voltage dependence, indicating its full orientation within the membrane. Titration experiments with chloroquine and different tetraalkylammonium ions suggested that the Ib channel was blocked by these compounds but had only a weak affinity to them. In vivo measurements using Vero cells demonstrate that chloroquine and related molecules also did not efficiently block intoxication of the cells by iota-toxin. The possible role of Ib in the translocation of iota-toxin across the target cell membrane is discussed.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				T. Neumeyer, B. Schiffler, E. Maier, A. E. Lang, K. Aktories, and R. Benz Clostridium botulinum C2 Toxin: IDENTIFICATION OF THE BINDING SITE FOR CHLOROQUINE AND RELATED COMPOUNDS AND INFLUENCE OF THE BINDING SITE ON PROPERTIES OF THE C2II CHANNEL J. Biol. Chem., February 15, 2008; 283(7): 3904 - 3914. [Abstract] [Full Text] [PDF]

				H. Barth, K. Aktories, M. R. Popoff, and B. G. Stiles Binary Bacterial Toxins: Biochemistry, Biology, and Applications of Common Clostridium and Bacillus Proteins Microbiol. Mol. Biol. Rev., September 1, 2004; 68(3): 373 - 402. [Abstract] [Full Text] [PDF]

				M. Nagahama, A. Yamaguchi, T. Hagiyama, N. Ohkubo, K. Kobayashi, and J. Sakurai Binding and Internalization of Clostridium perfringens Iota-Toxin in Lipid Rafts Infect. Immun., June 1, 2004; 72(6): 3267 - 3275. [Abstract] [Full Text] [PDF]

				D. Blocker, K. Pohlmann, G. Haug, C. Bachmeyer, R. Benz, K. Aktories, and H. Barth Clostridium botulinum C2 Toxin: LOW pH-INDUCED PORE FORMATION IS REQUIRED FOR TRANSLOCATION OF THE ENZYME COMPONENT C2I INTO THE CYTOSOL OF HOST CELLS J. Biol. Chem., September 26, 2003; 278(39): 37360 - 37367. [Abstract] [Full Text] [PDF]

				G. Haug, J. Leemhuis, D. Tiemann, D. K. Meyer, K. Aktories, and H. Barth The Host Cell Chaperone Hsp90 Is Essential for Translocation of the Binary Clostridium botulinum C2 Toxin into the Cytosol J. Biol. Chem., August 22, 2003; 278(34): 32266 - 32274. [Abstract] [Full Text] [PDF]