Linked Life Data

2332056

Source:http://linkedlifedata.com/resource/pubmed/id/2332056

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-6-6
pubmed:abstractText
Cellobiohydrolase I from Trichoderma reesei catalyzes the hydrolysis of methyl beta-D-cellotrioside (Km = 48 microM, kcat = 0.7 min-1) with release of the beta-cellobiose (retention of configuration). The same enzyme catalyzes the trans-hydration of cellobial (Km = 116 microM, kcat = 1.16 min-1) and lactal (Km = 135 microM, kcat = 1.35 min-1), presumably with glycosyl oxo-carbonium ion mediation. Protonation of the double bond is from the direction opposite that assumed for methyl beta-cellotrioside, but products formed from these prochiral substrates are again of beta configuration. Cellobiohydrolase II from the same microorganism hydrolyzes methyl beta-D-cellotetraoside (Km = 4 microM, kcat = 112 min-1) with inversion of configuration to produce alpha-cellobiose. The other reaction product, methyl beta-cellobioside, is in turn partly hydrolysed by cellobiohydrolase II to form methyl beta-D-glucoside and D-glucose, presumably the alpha-anomer. Reaction with cellobial is too slow to permit unequivocal determination of product configuration, but clear evidence is obtained that protonation occurs from the si-direction, again opposite that assumed for protonating glycosidic substrates. These results add substantially to the growing evidence that individual glycosidases create the anomeric configuration of their reaction products by means that are independent of substrate configuration.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
89-92
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Stereochemical course of hydrolysis and hydration reactions catalysed by cellobiohydrolases I and II from Trichoderma reesei.
pubmed:affiliation
Laboratorium voor Biochemie, State University Ghent, Belgium.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't