@article{AngelikaRolandoBeitzingeretal.2011,
  author    = {Angelika, Kronhardt and Rolando, Monica and Beitzinger, Christoph and Stefani, Caroline and Leuber, Michael and Flatau, Gilles and Popoff, Michel R. and Benz, Roland and Lemichez, Emmanuel},
  title     = {Cross-Reactivity of Anthrax and C2 Toxin: Protective Antigen Promotes the Uptake of Botulinum C2I Toxin into Human Endothelial Cells},
  series = {PLoS ONE},
  volume    = {6},
  journal   = {PLoS ONE},
  number    = {8},
  doi       = {10.1371/journal.pone.0023133},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134791},
  pages     = {e23133},
  year      = {2011},
  abstract  = {Binary toxins are among the most potent bacterial protein toxins performing a cooperative mode of translocation and exhibit fatal enzymatic activities in eukaryotic cells. Anthrax and C2 toxin are the most prominent examples for the AB(7/8) type of toxins. The B subunits bind both host cell receptors and the enzymatic A polypeptides to trigger their internalization and translocation into the host cell cytosol. C2 toxin is composed of an actin ADP-ribosyltransferase (C2I) and C2II binding subunits. Anthrax toxin is composed of adenylate cyclase (EF) and MAPKK protease (LF) enzymatic components associated to protective antigen (PA) binding subunit. The binding and translocation components anthrax protective antigen (PA(63)) and C2II of C2 toxin share a sequence homology of about 35\%, suggesting that they might substitute for each other. Here we show by conducting in vitro measurements that PA(63) binds C2I and that C2II can bind both EF and LF. Anthrax edema factor (EF) and lethal factor (LF) have higher affinities to bind to channels formed by C2II than C2 toxin's C2I binds to anthrax protective antigen (PA(63)). Furthermore, we could demonstrate that PA in high concentration has the ability to transport the enzymatic moiety C2I into target cells, causing actin modification and cell rounding. In contrast, C2II does not show significant capacity to promote cell intoxication by EF and LF. Together, our data unveiled the remarkable flexibility of PA in promoting C2I heterologous polypeptide translocation into cells.},
  language  = {de}
}
@article{BeitzingerStefaniKronhardtetal.2012,
  author    = {Beitzinger, Christoph and Stefani, Caroline and Kronhardt, Angelika and Rolando, Monica and Flatau, Gilles and Lemichez, Emanuel and Benz, Roland},
  title     = {Role of N-Terminal His6-Tags in Binding and Efficient Translocation of Polypeptides into Cells Using Anthrax Protective Antigen (PA)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76325},
  year      = {2012},
  abstract  = {It is of interest to define bacterial toxin biochemical properties to use them as molecular-syringe devices in order to deliver enzymatic activities into host cells. Binary toxins of the AB7/8-type are among the most potent and specialized bacterial protein toxins. The B subunits oligomerize to form a pore that binds with high affinity host cell receptors and the enzymatic A subunit. This allows the endocytosis of the complex and subsequent injection of the A subunit into the cytosol of the host cells. Here we report that the addition of an N-terminal His6-tag to different proteins increased their binding affinity to the protective antigen (PA) PA63-channels, irrespective if they are related (C2I) or unrelated (gpJ, EDIN) to the AB7/8-family of toxins. His6-EDIN exhibited voltage-dependent increase of the stability constant for binding by a factor of about 25 when the trans-side corresponding to the cell interior was set to 270 mV. Surprisingly, the C. botulinum toxin C2II-channel did not share this feature of PA63. Cell-based experiments demonstrated that addition of an N-terminal His6-tag promoted also intoxication of endothelial cells by C2I or EDIN via PA63. Our results revealed that addition of His6-tags to several factors increase their binding properties to PA63 and enhance the property to intoxicate cells.},
  subject      = {Biologie},
  language  = {en}
}