Linked Life Data

16667703

Source:http://linkedlifedata.com/resource/pubmed/id/16667703

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2010-6-29
pubmed:abstractText
Hydrogen peroxide (H(2)O(2)) scavenging systems of spruce (Picea abies) needles were investigated in both extracts obtained from the extracellular space and extracts of total needles. As assessed by the lack of activity of symplastic marker enzymes, the extracellular washing fluid was free from intracellular contaminations. In the extracellular washing fluid ascorbate, glutathione, cysteine, and high specific activities of guaiacol peroxidases were observed. Guaiacol peroxidases in the extracellular washing fluid and needle homogenates had the same catalytic properties, i.e. temperature optimum at 50 degrees C, pH optimum in the range of pH 5 to 6 and low affinity for guaiacol (apparent K(m) = 40 millimolar) and H(2)O(2) (apparent K(m) = 1-3 millimolar). Needle homogenates contained ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, glutathione reductase, and catalase, but not glutathione peroxidase activity. None of these activities was detected in the extracellular washing fluid. Ascorbate and glutathione related enzymes were freeze sensitive; ascorbate peroxidase was labile in the absence of ascorbate. The significance of extracellular antioxidants for the detoxification of injurious oxygen species is discussed.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Sep
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
94
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
312-9
pubmed:dateRevised
2010-9-14
pubmed:year
1990
pubmed:articleTitle
Composition and Properties of Hydrogen Peroxide Decomposing Systems in Extracellular and Total Extracts from Needles of Norway Spruce (Picea abies L., Karst.).
pubmed:affiliation
Fraunhofer Institut für Atmosphärische Umweltforschung, Kreuzeckbahnstr. 19, D-8100 Garmisch-Partenkirchen, Federal Republic of Germany.
pubmed:publicationType
Journal Article