Linked Life Data

10719177

Source:http://linkedlifedata.com/resource/pubmed/id/10719177

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-5-22
pubmed:abstractText
One basic peroxidase isoenzyme, with a pI of 8.8, is present in the intercellular washing fluid in the aerial part of 6-day-old Lupinus albus hypocotyl seedlings. This isoenzyme, called LuP-B2, is the principal soluble component secreted into the apoplastic space and it is a constitutive enzyme along the whole length of etiolated hypocotyl. The enzymatic inactivation process which this apoplastic peroxidase undergoes is described for the first time. The kinetic constants which describe its inactivation by H(2)O(2) in the absence of reductant substrates are determined. LuP-B2 is inactivated in situ and in vitro in a time- and concentration-dependent manner. H(2)O(2) acts as a suicide substrate according to a model previously proposed by us. The constant values calculated are similar to those calculated for the basic isoenzyme of horseradish roots, HRP-C. LuP-B2 presents a k(inact) value of 7.5 x 10(-3) s(-1) and a k(cat) of 6.7 s(-1). This isoenzyme makes 889 catalytic cycles for each inactivation event. The similarity in behavior and the constant values, together with other situations (both are excreted, soluble and constitutive isoenzymes) suggest that the inactivation process could play an important role in plant development and stress situations.
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
16
pubmed:volume
1478
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
78-88
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Characterization of isoperoxidase-B2 inactivation in etiolated Lupinus albus hypocotyls.
pubmed:affiliation
Department of Plant Biology (Plant Physiology), University of Murcia, 30100, Murcia, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't