Membrane translocation and channel-forming activities of diphtheria toxin are blocked by replacing isoleucine 364 with lysine.
A mutant of diphtheria toxin in which Ile-364 was replaced by Lys was at least 500-fold less toxic to Vero cells than the parental toxin. Its ability to undergo low-pH-triggered translocation across the plasma membrane was greatly diminished, as was its ability to form ion-conductive channels. In addition, the mutant toxin was inactive in the pH-dependent killing of Escherichia coli.
Cabiaux
V
V
Laboratoire des Macromolécules aux Interfaces, Université Libre de Bruxelles.
Mindell
J
J
Collier
R J
RJ
D000818:Animals; D001692:Biological Transport; D004167:Diphtheria Toxin / Q000737:chemistry* / Q000633:toxicity; D004926:Escherichia coli / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007473:Ion Channels / Q000737:chemistry*; D007532:Isoleucine / Q000737:chemistry; D008239:Lysine / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry; D016297:Mutagenesis, Site-Directed; D013329:Structure-Activity Relationship; D014709:Vero Cells / Q000187:drug effects
D004167:Diphtheria Toxin; D007473:Ion Channels; D008565:Membrane Proteins; D007532:Isoleucine; D008239:Lysine