PUBLICATION

Crosslinked Forms of the Isolated N-terminal Domain of the Lethal Factor are Potent Inhibitors of Anthrax Toxin

Authors
Juris, S.J., Melnyk, R.A., Bolcome, R.E., Chan, J., and Collier, R.J
ID
ZDB-PUB-070726-19
Date
2007
Source
Infection and Immunity   75(10): 5052-5058 (Journal)
Registered Authors
Bolcome, Robert, Chan, Joanne
Keywords
none
MeSH Terms
  • Animals
  • Anthrax/prevention & control
  • Antigens, Bacterial/metabolism
  • Antitoxins/chemistry*
  • Antitoxins/pharmacology*
  • Bacterial Toxins/antagonists & inhibitors*
  • Bacterial Toxins/metabolism
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Fish Diseases/prevention & control
  • Protein Structure, Tertiary
  • Zebrafish
PubMed
17635861 Full text @ Infect. Immun.
Abstract
The proteins that comprise anthrax toxin self-assemble at the mammalian cell surface into a series of toxic complexes, each containing a heptameric form of protective antigen (PA) plus up to three molecules, total, of the enzymic moieties of the toxin (lethal factor, LF, and edema factor, EF). These complexes are trafficked to the endosome, where the PA heptamer forms a pore in the membrane under the influence of low pH, and bound LF and EF unfold and translocate through the pore to the cytosol. To explore the hypothesis that the PA pore can translocate multiple, crosslinked polypeptides simultaneously, we crosslinked LFN, the N-terminal domain of LF, via an introduced cysteine at its N or C terminus and characterized the products. Both dimers and trimers of LFN retained the ability to bind to PA pores and block ion conductance, but were unable to translocate across the membrane, even at high voltages or with a transmembrane pH gradient. The multimers were remarkably potent inhibitors of toxin action in mammalian cells (20- to 50-fold more potent than monomeric LFN) and in a zebrafish model system. These findings show that the PA pore cannot translocate multimeric, crosslinked polypeptides and demonstrate a new approach to generating potent inhibitors of anthrax toxin.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping