Linked Life Data

18413313

Source:http://linkedlifedata.com/resource/pubmed/id/18413313

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
2008-6-9
pubmed:abstractText
Mammalian glycan chain elongation is mostly based on extending the type 2 chain, Galbeta1-4GlcNAc, whereas the corresponding type 1 chain, Galbeta1-3GlcNAc, is not normally extended. In a broader context of developing high sensitivity mass spectrometry methodologies for glycomic identification of Le(a) versus Le(x) and linear versus branched poly-N-acetyllactosamine (polyLacNAc), we have now shown that the dimeric type 1 glycan chain, as carried on the lactosylceramides of a human colonic adenocarcinoma cell line, Colo205, not only can be further extended linearly but can likewise be branched at C6 of 3-linked Gal in a manner similar to polyLacNAc. A combination of chemical and enzymatic derivatization coupled with advanced mass spectrometry analyses afforded unambiguous identification of a complex mixture of type 1 and 2 hybrids as well as those fucosylated variants founded exclusively on linear and branched trimeric type 1 chain. We further showed by in vitro enzymatic synthesis that extended type 1 and the hybrid chains can be branched by all three forms of the human I branching enzymes (IGnT) currently identified but with lower efficiency and stringency with respect to branching site preference. Importantly, it was found that a better substrate is one that carries a Gal site for branching that is extended at the non-reducing end by a type 2 and not a type 1 unit, whereas the IGnTs are less discriminative with respect to whether the targeted Gal site is itself beta3- or beta4-linked to GlcNAc at the reducing end.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
283
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
16455-68
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Identification of further elongation and branching of dimeric type 1 chain on lactosylceramides from colonic adenocarcinoma by tandem mass spectrometry sequencing analyses.
pubmed:affiliation
Institute of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't