Linked Life Data

16850501

Source:http://linkedlifedata.com/resource/pubmed/id/16850501

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2006-11-2
pubmed:abstractText
The synthesis of glycosides by enzymatic transglycosylation is a kinetically controlled reaction performed in the context of a non-favorable thermodynamic equilibrium. An unreactive organic cosolvent which increases the selectivity of the enzyme for glycosyl transfer to the acceptor nucleophile compared with water (Ksel) could improve maximum product yield. Here we report on the effect of the ionic liquid 1,3-dimethylimidazoliummethylsulfate on hydrolase and transferase activities of the hyperthermostable beta-glycosidase CelB from the archaeon Pyrococcus furiosus. CelB retained full catalytic efficiency for lactose hydrolysis at 80 degrees C in a 50% (by vol.) solution of ionic liquid in sodium citrate buffer, pH 5.5. It was inactive but not irreversibly denatured at 70% ionic liquid. Using lactose (0.15 M) as galactosyl donor, values of Ksel for a representative series of eight acceptor alcohols were determined in kinetic assays at 80 degrees C and found to increase between 1.3-fold (D-xylose) and 3.1-fold (glycerol) in 45% ionic liquid. Enhancement of Ksel was dependent on ionic liquid concentration and higher than expected from the decrease in water activity caused by the cosolvent. Experimental molar ratios of D-glucose and D-galactose produced during enzymatic conversion of lactose (75-150 mM) in the presence of D-xylose (0.5 M) or glycerol (0.5 M) showed excellent agreement with predictions based on Ksel values and confirm a significant, yet moderate effect of 45% ionic liquid on increasing the yield of D-galactoside product, by < or = 10%.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-3592
pubmed:author
pubmed:copyrightInfo
Copyright 2006 Wiley Periodicals, Inc.
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
95
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1093-100
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Influence of ionic liquid cosolvent on transgalactosylation reactions catalyzed by thermostable beta-glycosylhydrolase CelB from Pyrococcus Furiosus.
pubmed:affiliation
Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12, A-8010 Graz, Austria.
pubmed:publicationType
Journal Article