Amino acid and divalent ion permeability of the pores formed by the Bacillus thuringiensis toxins Cry1Aa and Cry1Ac in insect midgut brush border membrane vesicles

DOIResolve DOI: http://doi.org/10.1016/S0005-2736(02)00342-5
AuthorSearch for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for:
TypeArticle
Volume12
Issue2
Pages171179; # of pages: 9
Subjectenv
AbstractThe pores formed by Bacillus thuringiensis insecticidal toxins have been shown to allow the diffusion of a variety of monovalent cations and anions and neutral solutes. To further characterize their ion selectivity, membrane permeability induced by Cry1Aa and Cry1Ac to amino acids (Asp, Glu, Ser, Leu, His, Lys and Arg) and to divalent cations (Mg(2+), Ca(2+) and Ba(2+)) and anions (SO(4)(2-) and phosphate) was analyzed at pH 7.5 and 10.5 with midgut brush border membrane vesicles isolated from Manduca sexta and an osmotic swelling assay. Shifting pH from 7.5 to 10.5 increases the proportion of the more negatively charged species of amino acids and phosphate ions. All amino acids diffused well across the toxin-induced pores, but, except for aspartate and glutamate, amino acid permeability was lower at the higher pH. In the presence of either toxin, membrane permeability was higher for the chloride salts of divalent cations than for the potassium salts of divalent anions. These results clearly indicate that the pores are cation-selective.
Publication date
AffiliationNRC Biotechnology Research Institute; National Research Council Canada
Peer reviewedNo
NRC number45910
NPARC number3539541
Export citationExport as RIS
Report a correctionReport a correction
Record identifier6c428eb6-28dd-4c68-9a27-715d8e90f6e5
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)