Linked Life Data

8589416

Source:http://linkedlifedata.com/resource/pubmed/id/8589416

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-3-25
pubmed:abstractText
Syringomycin is a necrosis-inducing lipopeptide toxin synthesized and secreted by the phytopathogen, Pseudomonas syringae pv. syringae. Although small quantities of syringomycin are known to activate a cascade of physiological events in plasma membranes, the mechanism of action of the phytotoxin has never been fully characterized. The objective of this study was to test the hypothesis that the primary mode of action of syringomycin is to form transmembrane pores that are permeable to cations. Accordingly, direct measurement of ion fluxes were performed using artificial bilayers. The hemolytic properties and surface activity of HPLC-purified syringomycin were quantified by use of an erythrocyte lysis assay and by the drop weight method. Assays were performed using syringomycin form SRE alone or a mixture containing all forms of the phytotoxin. At a threshold concentration of 500 ng/ml, syringomycin induced hemolysis by forming ion channels in membranes. Osmotic protection studies indicated a channel radius of between 0.6 and 1 nm. The ion channel-forming activity was insensitive and permeable to both monovalent and divalent cations, suggesting that syringomycin causes lysis of erythrocytes by colloid osmotic lysis. In addition, syringomycin, like other lipopeptide antibiotics, is a potent biosurfactant capable of lowering the interfacial tension of water to 31 mN/m. The critical micellar concentration of syringomycin was calculated to be 1.25 mg/ml and the gamma CMC was 33 mN/m. A model is presented depicting the mechanism of action of syringomycin in the plant-pathogen interaction. The model integrates known effects of the toxin on ion flux in plasma membranes with formation of ion channels and the consequential cascade of effects associated with cellular signalling.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0894-0282
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
610-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Role of biosurfactant and ion channel-forming activities of syringomycin in transmembrane ion flux: a model for the mechanism of action in the plant-pathogen interaction.
pubmed:affiliation
Department of Plant Pathology, Washington State University, Pullman 99164-6430, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't