Linked Life Data

12162737

Source:http://linkedlifedata.com/resource/pubmed/id/12162737

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
2002-8-6
pubmed:abstractText
Amide exchange mass spectrometry (MS) was used to study the enzyme endopolygalacturonase II (EPG-II) from Aspergillus niger as it binds to an oligosaccharide substrate. A localized decrease in the level of deuterium incorporation in EPG-II of the EPG-II-oligosaccharide complex relative to that of the free EPG-II identified the location of substrate contact, which is in agreement with published site specific mutation studies. In addition, when bound with substrate, regions of EPG-II remote from the substrate binding site became exposed to the solvent, as revealed by an increase in the amount of incorporated deuterium, indicating a conformational change in the enzyme. Fluorescence experiments were performed to provide additional evidence for an altered conformation of EPG-II as a result of substrate binding. This novel application of amide exchange-MS to the study of protein-carbohydrate binding has, for the first time, described in detail the conformational changes associated with EPG-II when it binds a substrate. Amide exchange-MS was also used to study the interactions of EPG-II and the polygalacturonase inhibitor protein (PGIP). Mass spectral data of the EPG-II-oligosaccharide complex in the presence of Phaseolus vulgaris PGIP indicate that the inhibitor contacts EPG-II at a site remote from the substrate binding cleft, and is restricting the conformational changes of EPG-II. Fluorescence experiments also revealed that upon binding of PGIP, the conformational changes mentioned above for the EPG-II-substrate complex are minimized. These results, together with previously reported data, point to a location on EPG-II for interaction with PGIP as well as a possible mechanism for noncompetitive inhibition of EPG-II.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10225-33
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Use of amide exchange mass spectrometry to study conformational changes within the endopolygalacturonase II-homogalacturonan-polygalacturonase inhibiting protein system.
pubmed:affiliation
Complex Carbohydrate Research Center, Department of Chemistry, University of Georgia, 220 Riverbend Road, Athens, Georgia 30602-4712, USA.
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