Plant Physiol.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Web of Science (7)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Nielsen, T. H.
Right arrow Articles by Wischmann, B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nielsen, T. H.
Right arrow Articles by Wischmann, B.
Agricola
Right arrow Articles by Nielsen, T. H.
Right arrow Articles by Wischmann, B.

PLANT PHYSIOLOGY , Vol 109, Issue 3 1033-1038, Copyright © 1995 by American Society of Plant Biologists

BIOCHEMISTRY AND ENZYMOLOGY

Quantitative Aspects of the in Vivo Regulation of Pyrophosphate:Fructose-6-Phosphate 1-Phosphotransferase by Fructose-2,6-Bisphosphate

T. H. Nielsen and B. Wischmann
Plant Biochemistry Laboratory, Department of Plant Biology, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Copenhagen, Denmark

Pyrophosphate:fructose-6-phosphate 1-phosphotransferase (PFP) was quantified in developing barley (Hordeum vulgare) leaves by immunostaining on western blots using a purified preparation of barley leaf PFP as standard. Fructose-2,6-bisphosphate (Fru-2,6-bisP) was quantified in the same tissues. Depending on age and tissue development, the concentration of PFP varied between 11 and 80 [mu]g PFP protein g-1 fresh weight, which corresponds to 0.09 to 0.65 nmol g-1 fresh weight of each of the [alpha] and [beta] PFP subunits. The level depends primarily on the maturity of the tissue. In the same tissues the concentration of Fru-2,6-bisP varied between 0.07 and 0.46 nmol g-1 fresh weight. Thus, the concentrations of PFP subunits and Fru-2,6-bisP were of the same order of magnitude. In young leaf tissues the concentration of PFP subunits may exceed the concentration of Fru-2,6-bisP. This means that the amount of Fru-2,6-bisP present will be too low to occupy all the allosteric binding sites on PFP even though the concentration of Fru-2,6-bisP exceeds the Ka(Fru-2,6-bisP) by several orders of magnitude. These results are discussed in relation to Fru-2,6-bisP as a regulator of enzyme activities under in vivo conditions.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 1995 by the American Society of Plant Biologists