Linked Life Data

8457588

Source:http://linkedlifedata.com/resource/pubmed/id/8457588

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1993-4-28
pubmed:abstractText
The mode of action of three genetically distinct endo-beta-1,4-xylanases (EXs) of Streptomyces lividans, XlnA, XlnB and XlnC, belonging to two different xylanase families, was investigated on a variety of polysaccharide and oligosaccharide substrates. Viscosimetric measurements showed that all three enzymes have about the same endo-acting character. Occurrence of multiple pathways of substrate degradation at high concentration of beta-1,4-xylooligosaccharides suggested that all three enzymes were retaining glycanases. The enzymes differed considerably in their mode of action on various heteroxylans and on rhodymenan. XlnA hydrolyzed all tested polysaccharides to a higher degree than XlnB or XlnC, through liberation of smaller hydrolysis products, both linear or branched. XlnA performed much better than XlnB or XlnC, particularly on acetylxylan, liberating large amounts of short acetylated and non-acetylated fragments. XlnB and XlnC liberated from acetylxylan only limited amounts of larger acetylated fragments. XlnA exhibited also much higher catalytic efficiency than the other two EXs on short beta-1,4-xylooligosaccharides. The kinetic parameters and bond-cleavage frequencies determined for xylotriose, xylotetraose and xylopentaose using 1-3H-reducing-end-labelled compounds suggested that the substrate binding site of XlnA is smaller and differently organized than those in XlnB or XlnC. In contrast to XlnB and XlnC, XlnA also exhibited significant aryl-beta-xylosidase activity. No distinctive catalytic properties of either XlnB or XlnC were found which were not inherent also to XlnA. High-molecular-mass EXs of the XlnA type show much greater catalytic versatility due than low-molecular-mass EXs of the XlnB or XlnC type.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
1162
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
246-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Mode of action of three endo-beta-1,4-xylanases of Streptomyces lividans.
pubmed:affiliation
Centre de Recherche en Microbiologie Appliquée, Institut Armand-Frappier, Université du Québec, Ville de Laval, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't