Linked Life Data

12423964

Source:http://linkedlifedata.com/resource/pubmed/id/12423964

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
2002-11-8
pubmed:abstractText
Conformational analyses of the branched repeating unit of the O-antigenic polysaccharide of Shigella dysenteriae type 2 have been performed with molecular mechanics MM3. A filtered systematic search on the trisaccharide alpha-D-GalNAc-(1-->3)-[alpha-D-GlcNAc-(1-->4)]-alpha-D-GalNAc forming the branch, shows essentially a single favored conformation. Also, the downstream alpha-D-GalNAc-(1-->4)-alpha-D-Glc linkage is sterically constrained. The alpha-D-Glc-(1-->4)-beta-D-Gal moiety, however, forms a more flexible link region between the branch points, and shows a 90 degrees bend similar to what is known for the galabiose moiety occurring in globo-glycolipids. The calculations indicate that consecutive repeating units in their minimum energy conformation arrange in a helical structure with three repeating units per turn. This helix is very compact and appears to be stabilized by hydrophobic interactions involving the N-acetyl groups at the branch points. Random conformational search suggests the existence of another helical structure with four repeating units per turn. It appears possible that the alpha-D-Glc-(1-->4)-beta-D-Gal moiety, which is exposed on the surface of the helical structures, can evade recognition by the immune system of the host by the mimicry of globo structures.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0008-6215
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
337
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1633-40
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Conformation of the branched O-specific polysaccharide of Shigella dysenteriae type 2: molecular mechanics calculations show a compact helical structure exposing an epitope which potentially mimics galabiose.
pubmed:affiliation
Department of Medical Biochemistry, Centre for Structural Biology, Göteborg University, Medicinaregatan 7B, SE-405 30, Göteborg, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't