Open AccessBeticolins, Nonpeptidic, Polycyclic Molecules Produced by the Phytopathogenic Fungus Cercospora beticola, as a New Family of Ion Channel-Forming Toxins
Author(s) -
Cyril Goudet,
MarieLouise Milat,
Hervé Sentenac,
JeanBaptiste Thibaud
Publication year - 2000
Publication title -
molecular plant-microbe interactions
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.565
H-Index - 153
eISSN - 1943-7706
pISSN - 0894-0282
DOI - 10.1094/mpmi.2000.13.2.203
Subject(s) - chemistry , stereochemistry , conductance , ion channel , molecule , residue (chemistry) , biochemistry , organic chemistry , mathematics , combinatorics , receptor
Beticolins are toxins produced by Cercospora beticola, a phytopathogenic fungus responsible for the leaf spot disease of sugar beet. They form a family of 20 nonpeptidic compounds (named B0 to B19) that share the same polycyclic skeleton but differ by isomeric configuration (ortho- or para-) and by a variable residue R (bridging two carbons in one of the six cycles). It has been previously shown that B0 assembles itself into a multimeric structure and forms ion channels into planar lipid bilayers (C. Goudet, A.-A. Véry, M.-L. Milat, M. Ildefonse, J.-B. Thibaud, H.Sentenac, and J.-P. Blein, Plant J. 14:359-364, 1998). In the present work, we investigate pore formation by three ortho-beticolins, B0, B2, and B4, and their related (i.e., same R) para-isomers, B13, B1, and B3, respectively, using planarlipid bilayers. All beticolins were able to form ionchannels with multiple conductance states, although the type of cyclization (ortho- or para-) and residue (R) result in variations of channel conductance and ionic permeability, respectively. Channel formation by beticolins is likely to be involved in the biological activity of these toxins.