Linked Life Data

10779871

Source:http://linkedlifedata.com/resource/pubmed/id/10779871

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2000-7-27
pubmed:abstractText
In preparation for the development of a xylitol biosensor, the xylitol dehydrogenase of Candida tropicalis IFO 0618 was partially purified and characterized. The optimal pH and temperature of the xylitol dehydrogenase were pH 8.0 and 50 degrees C, respectively. Of the various alcohols tested, xylitol was the most rapidly oxidized, with sorbitol and ribitol being reduced at 65% and 58% of the xylitol rate. The enzyme was completely inactive on arabitol, xylose, glucose, glycerol, and ethanol. The enzyme's xylitol oxidation favored the use of NAD+ (7.9 U/mg) over NADP+ (0.2 U/mg) as electron acceptor, while the reverse reaction, D-xylulose reduction, favored NADPH (7.7 U/mg) over NADH (0.2 U/mg) as electron donor. The K(m) values for xylitol and NAD+ were 49.8 mM and 38.2 microM, respectively. For the generation of the xylitol biosensor, the above xylitol dehydrogenase and a diaphorase were immobilized on bromocyan-activated sephallose. The gel was then attached on a dissolved oxygen electrode. In the presence of vitamin K3, NAD+ and phosphate buffer, the biosensor recorded a linear response to xylitol concentration up to 3 mM. The reaction was stable after 15 min. When the biosensor was applied to a flow injection system, optimal operation pH and temperature were 8.0 and 30 degrees C, respectively. The strengths and limitations of the xylitol biosensor are its high affinity for NAD+, slow reaction time, narrow linear range of detection, and moderate affinity for xylitol.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0008-4166
pubmed:author
pubmed:issnType
Print
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
350-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Development of a xylitol biosensor composed of xylitol dehydrogenase and diaphorase.
pubmed:affiliation
Department of Bioprocessing, Faculty of Agriculture, Gifu University, Japan. tak2003@cc.gifu-u.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't