Linked Life Data

16716279

Source:http://linkedlifedata.com/resource/pubmed/id/16716279

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2006-7-17
pubmed:abstractText
In the presence of suitable acceptor molecules, dextransucrase makes a homologous series of oligosaccharides in which the isomers differ by a single glucosyl unit, whereas alternansucrase synthesizes one trisaccharide, two tetrasaccharides, etc. For the example of maltose as the acceptor, if one considers only the linear, unbranched possibilities for alternansucrase, the hypothetical number of potential products increases exponentially as a function of the degree of polymerization (DP). Experimental evidence indicates that far fewer products are actually formed. We show that only certain isomers of DP >4 are formed from maltose in measurable amounts, and that these oligosaccharides belong to the oligoalternan series rather than the oligodextran series. When the oligosaccharide acceptor products from maltose were separated by size-exclusion chromatography and HPLC, only one pentasaccharide was isolated. Its structure was alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->4)-D-Glc. Two hexasaccharides were formed in approximately equal quantities: alpha-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->4)-D-Glc and alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->4)-D-Glc. Just one heptasaccharide was isolated from the reaction mixture, alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->3)-alpha-D-Glcp-(1-->6)-alpha-D-Glcp-(1-->4)-D-Glc. We conclude that the enzyme is incapable of forming two consecutive alpha-(1-->3) linkages, and does not form products with more than two consecutive alpha-(1-->6) linkages. The distribution of products may be kinetically determined.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0008-6215
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
341
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2066-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Penta-, hexa-, and heptasaccharide acceptor products of alternansucrase.
pubmed:affiliation
Bioproducts and Biocatalysis Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, 1815 North University Street, Peoria, IL 61604, USA. cotegl@ncaur.usda.gov
pubmed:publicationType
Journal Article