Linked Life Data

9007276

Source:http://linkedlifedata.com/resource/pubmed/id/9007276

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1997-4-9
pubmed:abstractText
The bacterial protein enterotoxins, cholera toxin (CT) of Vibrio cholerae and heat-labile toxin (LT) of Escherichia coli, induce diarrhea by enhancing the secretory activity of the small intestine of man and rabbit (animal model). This physiological effect is mediated by toxin binding to a glycolipid receptor, the ganglioside GM1, Gal beta 3GalNAc beta 4(NeuAc alpha 3)GAl beta 4Glc beta 1Cer. However, LT, but not CT, was recently shown by us to bind also to paragloboside, Gal beta 4GlcNAc beta 3Gal beta 4Glc beta 1Cer, identified in the target cells. By molecular modeling of this tetrasaccharide in the known binding site of LT, the saccharide-peptide interaction was shown to be limited to the terminal disaccharide (N-acetyllactosamine). This sequence is expressed in many glycoconjugates, and we have therefore assayed glycolipids and glycoproteins prepared from the target tissues. In addition to paragloboside, receptor activity for LT was detected in glycoproteins of human origin and in polyglycosylceramides of rabbit. However, CT bound only to GM1. Two variants of LT with slightly different sequences, human (hLT) and porcine (pLT), were identical in their binding to target glycoproteins and polyglycosylceramides, but different regarding paragloboside, which was positive for pLT but negative for hLT. This difference is discussed on basis of modeling, taking in view the difference at position 13, with Arg in pLT and His in hLT. Although N-acetyllactosamine is differently recognized in form of paragloboside by the two toxin variants, we speculate that this sequence in human glycoproteins and rabbit polyglycosylceramides is the basis for the common binding. Much work remains, however, to clear up up this unexpected sophistication in target recognition.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0968-0896
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1919-28
pubmed:dateRevised
2008-8-20
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Unexpected carbohydrate cross-binding by Escherichia coli heat-labile enterotoxin. Recognition of human and rabbit target cell glycoconjugates in comparison with cholera toxin.
pubmed:affiliation
Department of Medical Biochemistry, Göteborg University, Sweden.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't