Linked Life Data

16377616

Source:http://linkedlifedata.com/resource/pubmed/id/16377616

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2006-2-27
pubmed:abstractText
Escherichia coli alpha-hemolysin (HlyA) is a protein exotoxin that binds and lyses eukaryotic cell and model membranes in the presence of calcium. Previous studies have been able to distinguish between reversible toxin binding to the membrane and irreversible insertion into the lipid matrix. Membrane lysis occurs as the combined effect of protein insertion plus a transient perturbation of the membrane bilayer structure. In the past, insertion and bilayer perturbation have not been experimentally dissected. This has now been achieved by studying HlyA penetration into lipid monolayers at the air-water interface, in which three-dimensional effects (of the kind required to break down the bilayer permeability barrier) cannot occur. The study of native HlyA, together with the nonlytic precursor pro-HlyA, and of different mutants demonstrates that although some nonlytic variants (e.g. pro-HlyA) exhibit very low levels of insertion, others (e.g. the nonlytic mutant HlyA H859N) insert even more strongly than the lytic wild type. These results show that insertion does not necessarily lead to membrane lysis, i.e. that insertion and lysis are not "coupled" phenomena. Millimolar levels of Ca(2+), which are essential for the lytic activity, cause an extra degree of insertion but only in the case of the lytic forms of HlyA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5461-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Membrane insertion of Escherichia coli alpha-hemolysin is independent from membrane lysis.
pubmed:affiliation
Unidad de Biofísica (Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea), and Departamento de Bioquímica, Universidad del País Vasco, Aptdo. 644, 48080 Bilbao, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't