Linked Life Data

18512955

Source:http://linkedlifedata.com/resource/pubmed/id/18512955

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
2010-3-24
pubmed:abstractText
Two long-standing questions about glucansucrases (EC 2.4.1.5) are how they control oligosaccharide versus polysaccharide synthesis and how they direct their glycosidic linkage specificity. This information is required for the production of tailor-made saccharides. Mutagenesis promises to be an effective tool for enzyme engineering approaches for altering the regioselectivity and acceptor substrate specificity. Therefore, we chose the most conserved motif around the transition state stabilizer in glucansucrases for a random mutagenesis of the glucansucrase GTFR of Streptococcus oralis, yielding different variants with altered reaction specificity. Modifications at position S628 achieved by saturation mutagenesis guided the reaction toward the synthesis of short chain oligosaccharides with a drastically increased yield of isomaltose (47%) or leucrose (64%). Alternatively, GTFR variant R624G/V630I/D717A exhibited a drastic switch in regioselectivity from a dextran type with mainly alpha-1,6-glucosidic linkages to a mutan type polymer with predominantly alpha-1,3-glucosidic linkages. Targeted modifications demonstrated that both mutations near the transition state stabilizer, R624G and V630I, are contributing to this alteration. It is thus shown that mutagenesis can guide the transglycosylation reaction of glucansucrase enzymes toward the synthesis of (a) various short chain oligosaccharides or (b) novel polymers with completely altered linkages, without compromising their high transglycosylation activity and efficiency.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1520-4995
pubmed:author
pubmed:issnType
Electronic
pubmed:day
24
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6678-84
pubmed:meshHeading
pubmed-meshheading:18512955-Amino Acid Sequence, pubmed-meshheading:18512955-Bacterial Proteins, pubmed-meshheading:18512955-Carbohydrate Sequence, pubmed-meshheading:18512955-Chromatography, Thin Layer, pubmed-meshheading:18512955-Enzyme Assays, pubmed-meshheading:18512955-Glucans, pubmed-meshheading:18512955-Glucosyltransferases, pubmed-meshheading:18512955-Glycosides, pubmed-meshheading:18512955-Glycosylation, pubmed-meshheading:18512955-Glycosyltransferases, pubmed-meshheading:18512955-Hydrolysis, pubmed-meshheading:18512955-Kinetics, pubmed-meshheading:18512955-Molecular Sequence Data, pubmed-meshheading:18512955-Molecular Structure, pubmed-meshheading:18512955-Mutation, pubmed-meshheading:18512955-Oligosaccharides, pubmed-meshheading:18512955-Polymers, pubmed-meshheading:18512955-Protein Engineering, pubmed-meshheading:18512955-Streptococcus oralis, pubmed-meshheading:18512955-Substrate Specificity
pubmed:year
2008
pubmed:articleTitle
Engineering the glucansucrase GTFR enzyme reaction and glycosidic bond specificity: toward tailor-made polymer and oligosaccharide products.
pubmed:affiliation
Department of Carbohydrate Technology, University of Braunschweig, Braunschweig, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't