Linked Life Data

3289613

Source:http://linkedlifedata.com/resource/pubmed/id/3289613

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1988-8-1
pubmed:abstractText
Crystalline Aspergillus niger alpha-glucosidase and highly purified preparations of rice alpha-glucosidase II and Trichoderma reesei trehalase were found to catalyze the hydration of [2-(2)H]-D-gluco-octenitol, i.e., (Z)-3,7-anhydro-1,2-dideoxy-[2-2H]-D-gluco-oct-2-enitol, to yield 1,2-dideoxy-[2-2H]-D-gluco-octulose. In each case, the stereochemistry of the reaction was elucidated by examining the newly formed centers of asymmetry at C-2 and C-3 of the hydration product. The C-1 to C-3 fragment of each isolated [2-2H]-D-gluco-octulose product was recovered as [2-2H]propionic acid and identified by its positive optical rotatory dispersion as the S isomer, showing that each enzyme had protonated the octenitol (at C-2) from above its re face. 1H NMR spectra of enzyme/D-gluco-octenitol digests in D2O showed that the alpha-anomer of [2-2H]-D-gluco-octulose was exclusively produced by each alpha-glucosidase, whereas the beta-anomer was formed by action of the trehalase. The trans hydration catalyzed by the alpha-glucosidases was found to be very strongly inhibited by the substrate; the cis hydration reaction catalyzed by the trehalase showed no such inhibition. Special importance is attached to the finding that in hydrating octenitol each enzyme creates a product of the same anomeric form as in hydrolyzing an alpha-D-glucosidic substrate. This result adds substantially to the growing evidence that individual glycosylases create the configuration of their reaction products by a means that is independent of donor substrate configuration, that is, by a means other than "retaining" or "inverting" substrate configuration.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2294-300
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Steric course of the hydration of D-gluco-octenitol catalyzed by alpha-glucosidases and by trehalase.
pubmed:affiliation
Chemisches Laboratorium, Universität Freiburg, West Germany.
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