Linked Life Data

2901352

Source:http://linkedlifedata.com/resource/pubmed/id/2901352

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1988-10-21
pubmed:abstractText
A nicked theta-toxin (C theta), obtained by limited proteolysis with subtilisin Carlsberg, causes almost no hemolysis while it retains a nearly intact cholesterol binding site below 20 degrees C. Neither electron microscopic evidence for the formation of arc- and ring-shaped structures on the membrane nor toxin-stimulated influx of extracellular Ca2+ are detected in C theta-treated cells below 20 degrees C. Thus, event(s) in the lytic process are responsible for the temperature dependency of hemolysis, which is also supported by the observation that C theta requires higher Arrhenius activation energy for hemolysis than the native toxin. Using C theta as a probe due to its high affinity for membrane cholesterol without causing any obvious membrane changes, we demonstrated the possible existence of high- and low-affinity sites for theta-toxin on sheep erythrocytes. Both binding sites disappear by simultaneous treatment of the cells with sublytic doses of digitonin. Furthermore, C theta binds only to cholesterol among the chloroform/methanol-extractable, lipid components of sheep and human erythrocytes but not to the protein components derived from them. These results strongly suggest that cholesterol is an essential component of the both high- and low-affinity sites, and also imply that the modes of existence of cholesterol in the red cell membrane are heterogeneous.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
176
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
95-101
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Protease-nicked theta-toxin of Clostridium perfringens, a new membrane probe with no cytolytic effect, reveals two classes of cholesterol as toxin-binding sites on sheep erythrocytes.
pubmed:affiliation
Department of Biochemistry, Tokyo Metropolitan Institute of Gerontology, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't