Linked Life Data

15996100

Source:http://linkedlifedata.com/resource/pubmed/id/15996100

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
27
pubmed:dateCreated
2005-7-5
pubmed:abstractText
A quartz-crystal microbalance (QCM) technique was applied to analyze effects of site-directed mutagenesis of a glycosidase (isomalto-dextranase) on the hydrolysis mechanism of the substrate binding (k(on), k(off), and K(d)) and the catalytic process (k(cat)), separately, by using a dextran-immobilized QCM in buffer solution. D266N, D198N, and D313N mutants, which are predicted as critical residues of the isomalto-dextranase hydrolytic activity, dramatically decreased the apparent enzyme activity. The D266N mutant, however, did not change the substrate binding ability (K(d)), and the D198N and D313N mutants largely increased K(d) values due to the increase of k(off) and/or the decrease of k(on) values, as well as the negatively small k(cat) values. From these results, we estimate the reaction mechanism, in which Asp266 acts as only a general acid in the catalytic process, Asp198 acts as both nucleophile in the catalytic process and binding the substrate, and Asp313 acts as only the substrate binding.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9456-61
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Kinetic studies of site-directed mutational isomalto-dextranase-catalyzed hydrolytic reactions on a 27 MHz quartz-crystal microbalance.
pubmed:affiliation
Department of Biomolecular Engineering, Frontier Collaborative Research Center, Tokyo Institute of Technology and CREST, Japan Science and Technology Corporation, Yokohama 226-8501, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't