Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
2000-5-4
pubmed:abstractText
The activation of oxidized phosphoribulokinase either "free" or as part of a bi-enzyme complex by reduced thioredoxins during the enzyme reaction was studied. In the presence of reduced thioredoxin, the product of the reaction catalyzed by phosphoribulokinase within the bi-enzyme complex does not appear in a linear fashion. It follows a mono-exponential pattern that suggests a slow dissociation process of the bi-enzyme complex in the assay cuvette. A plot of the steady state of product appearance against thioredoxin concentration gave a sigmoid curve. On the basis of our experimental results, we propose a minimum model of the activation of phosphoribulokinase by reduced thioredoxin. Reduced thioredoxin may act on the phosphoribulokinase, either within the complex or in the dissociated metastable form. However, the time required to activate the enzyme as part of the complex is shorter (about 20 s) than that required to activate the dissociated form (about 10 min). This might be of physiological relevance, and we discuss the role of the interactions between phosphoribulokinase and glyceraldehyde-3-phosphate dehydrogenase in the regulation of the Calvin cycle.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9447-51
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Thioredoxin activation of phosphoribulokinase in a bi-enzyme complex from Chlamydomonas reinhardtii chloroplasts.
pubmed:affiliation
Institut Jacques MONOD (UMR 7592), CNRS-Universités Paris VI-VII, 2 Place Jussieu, 75251 Paris Cedex 05, France.
pubmed:publicationType
Journal Article