Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
1991-5-13
pubmed:abstractText
The sulfated polysaccharides occurring in the tunic of ascidians are unique among known sulfated polysaccharides in that their major constituent sugar is galactose, which occurs exclusively in the L-enantiomeric form. In vitro incorporation experiments using tunic slices incubated with 14C-labeled sugars revealed that cells from this tissue epimerize D-isomers of hexose into L-galactose during the biosynthesis of their constituent polysaccharides. Compared with other hexoses, the precursor D-[14C]glucose has the highest rate of incorporation and produces the highest proportion of L-galactose units. This metabolic pathway is distinct from the epimerization of D-mannose to L-galactose through its guanosine 5'-diphosphate nucleotide, described previously in an alga and in a snail. Therefore, the epimerization of D-glucose to L-galactose in the ascidian tunic occurs through a novel metabolic route, which involves inversion of the configuration of carbon atoms 2, 3, and 5 of the hexosyl moieties.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3458-64
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Epimerization of D-glucose to L-galactose during the biosynthesis of a sulfated L-galactan in the ascidian tunic.
pubmed:affiliation
Departamento de Bioquímica, Universidade Federal do Rio de Janeiro, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't