Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
46
pubmed:dateCreated
2003-11-10
pubmed:abstractText
Pore formation in the target cell membranes is a common mechanism used by many toxins in order to kill cells. Among various described mechanisms, a toroidal pore concept was described recently in the course of action of small antimicrobial peptides. Here we provide evidence that such mechanism may be used also by larger toxins. Membrane-destabilizing effects of equinatoxin II, a sea anemone cytolysin, were studied by various biophysical techniques. 31P NMR showed an occurrence of an isotropic component when toxin was added to multilamellar vesicles and heated. This component was not observed with melittin, alpha-staphylococcal toxin, or myoglobin. It does not originate from isolated small lipid structures, since the size of the vesicles after the experiment was similar to the control without toxin. Electron microscopy shows occurrence of a honeycomb structure, previously observed only for some particular lipid mixtures. The analysis of FTIR spectra of the equinatoxin II-lipid complex showed lipid disordering that is consistent with isotropic component observed in NMR. Finally, the cation selectivity of the toxin-induced pores increased in the presence of negatively charged phosphatidic acid, indicating the presence of lipids in the conductive channel. The results are compatible with the toroidal pore concept that might be a general mechanism of pore formation for various membrane-interacting proteins or peptides.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
45216-23
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:12944411-Animals, pubmed-meshheading:12944411-Cations, pubmed-meshheading:12944411-Cell Membrane, pubmed-meshheading:12944411-Cnidarian Venoms, pubmed-meshheading:12944411-Ions, pubmed-meshheading:12944411-Light, pubmed-meshheading:12944411-Lipid Metabolism, pubmed-meshheading:12944411-Magnetic Resonance Spectroscopy, pubmed-meshheading:12944411-Microscopy, Electron, pubmed-meshheading:12944411-Peptides, pubmed-meshheading:12944411-Phosphatidic Acids, pubmed-meshheading:12944411-Scattering, Radiation, pubmed-meshheading:12944411-Sea Anemones, pubmed-meshheading:12944411-Spectrophotometry, Infrared, pubmed-meshheading:12944411-Spectroscopy, Fourier Transform Infrared, pubmed-meshheading:12944411-Staphylococcus aureus, pubmed-meshheading:12944411-Temperature, pubmed-meshheading:12944411-Time Factors, pubmed-meshheading:12944411-Toxins, Biological, pubmed-meshheading:12944411-Whales
pubmed:year
2003
pubmed:articleTitle
Pore formation by equinatoxin II, a eukaryotic protein toxin, occurs by induction of nonlamellar lipid structures.
pubmed:affiliation
Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, 1000 Ljubljana, Slovenia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't