Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 275, Issue 13, Pages 9447-9451Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.275.13.9447
Keywords
-
Categories
Ask authors/readers for more resources
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.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available