Blepharismins, produced by the protozoan, Blepharisma japonicum, form ion-permeable channels in planar lipid bilayer membranes

Citation
Y. Muto et al., Blepharismins, produced by the protozoan, Blepharisma japonicum, form ion-permeable channels in planar lipid bilayer membranes, FEBS LETTER, 508(3), 2001, pp. 423-426
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
FEBS LETTERS
ISSN journal
0014-5793 → ACNP
Volume
508
Issue
3
Year of publication
2001
Pages
423 - 426
Database
ISI
SICI code
0014-5793(20011123)508:3<423:BPBTPB>2.0.ZU;2-L
Abstract
Blepharismins are polycyclic quinones found in the pigment granules of the ciliated protozoan, Blepharisma. Exposure to purified blepharismins results in lethal damage to several other ciliates. We here report that, at cytoto xic concentrations, blepharismins formed cation-selective channels in plana r phospholipid bilayer membranes. The channels formed in a diphytanoylphosp hatidylcholine bilayer had a K+/Cl- permeability ratio of 6.6:1. Single cha nnel recordings revealed the conductance to be quite heterogeneous, ranging from 0.2 to 2.8 nS in solutions containing 0.1 M KCl, possibly reflecting different states of aggregation of blepharismin. Our observations suggest t hat channel formation is a cytotoxic mechanism of blepharismin's action aga inst predatory protozoa. (C) 2001 Federation of European Biochemical Societ ies. Published by Elsevier Science B.V. All rights reserved.