Membrane translocation and channel-forming activities of diphtheria toxin are blocked by replacing isoleucine 364 with lysine.
نویسندگان
چکیده
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.
منابع مشابه
Replacement of negative by positive charges in the presumed membrane-inserted part of diphtheria toxin B fragment. Effect on membrane translocation and on formation of cation channels.
Diphtheria toxin B fragment is capable of forming cation-selective channels in the plasma membrane. Such channels may be involved in the translocation of the toxin A fragment to the cytosol. Seven negatively charged amino acids in the B fragment were replaced one by one by lysines, followed by studies of cytotoxicity and channel-forming ability of the different mutants. The mutant D392K showed ...
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عنوان ژورنال:
- Infection and immunity
دوره 61 5 شماره
صفحات -
تاریخ انتشار 1993