Estimation of the radius of the pores formed by the Bacillus thuringiensis Cry1C delta-endotoxin in planar lipid bilayers

Download
  1. Get@NRC: Estimation of the radius of the pores formed by the Bacillus thuringiensis Cry1C delta-endotoxin in planar lipid bilayers (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1016/S0005-2736(02)00605-3
AuthorSearch for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for:
TypeArticle
Journal titleBiochimica et Biophysica Acta (BBA) - Biomembranes
Volume1567
Pages113122; # of pages: 10
Subjectenv; Cry1C δ-endotoxin; Planar lipid bilayer; Ion channel; Polyethylene glycol; Pore size; Bacillus thuringiensis
AbstractPore formation constitutes a key step in the mode of action of Bacillus thuringiensis δ-endotoxins and various activated Cry toxins have been shown to form ionic channels in receptor-free planar lipid bilayers at high concentrations. Multiple conductance levels have been observed with several toxins, suggesting that the channels result from the multimeric assembly of a variable number of toxin molecules. To test this possibility, the size of the channels formed by Cry1C was estimated with the non-electrolyte exclusion technique and polyethylene glycols of various molecular weights. In symmetrical 300 mM KCl solutions, Cry1C induced channel activity with 15 distinct conductance levels ranging from 21 to 246 pS and distributed in two main conductance populations. Both the smallest and largest conductance levels and the mean conductance values of both populations were systematically reduced in the presence of polyethylene glycols with hydrated radii of up to 1.05 nm, indicating that these solutes can penetrate the pores formed by the toxin. Larger polyethylene glycols had little effect on the conductance levels, indicating that they were excluded from the pores. Our results indicate that Cry1C forms clusters composed of a variable number of channels having a similar pore radius of between 1.0 and 1.3 nm and gating synchronously.
Publication date
LanguageEnglish
AffiliationNRC Biotechnology Research Institute; National Research Council Canada
Peer reviewedNo
NRC number45890
NPARC number3539754
Export citationExport as RIS
Report a correctionReport a correction
Record identifier23285506-abd1-4653-a762-39bc351aa029
Record created2009-03-01
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)