Putative ornithine decarboxylase activity in Arabidopsis thaliana: inhibition and intracellular localisation

In this work we studied putative ornithine decarboxylase activity (ODC, EC 4.1.1.17) in leaves of Arabidopsis thaliana L. (ecotype Columbia) plants at non-flowering stage (about 21 d of culture). Putative ODC activity was higher in the particulate than in the soluble fraction and activity was pH-dep...

Full description

Saved in:
Bibliographic Details
Published in:Plant physiology and biochemistry 2003-10, Vol.41 (10), p.871-875
Main Authors: Tassoni, Annalisa, Fornalè, Silvia, Bagni, Nello
Format: Article
Language:English
Subjects:
ACTIVIDAD ENZIMÁTICA
ACTIVITÉ ENZYMATIQUE
ARABIDOPSIS THALIANA
ENZYME ACTIVITY
ESPERMIDINA
FEUILLE
HOJAS
INHIBICIÓN
INHIBITION
LEAVES
LIASAS
LYASE
LYASES
ORNITHINE
Ornithine decarboxylase
ORNITINA
POLIAMINAS
POLYAMINE
POLYAMINES
PUTRESCINA
PUTRESCINE
SPERMIDINE
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In this work we studied putative ornithine decarboxylase activity (ODC, EC 4.1.1.17) in leaves of Arabidopsis thaliana L. (ecotype Columbia) plants at non-flowering stage (about 21 d of culture). Putative ODC activity was higher in the particulate than in the soluble fraction and activity was pH-dependent, increasing linearly with the pH. Inclusion of 10 mM arginine in the assay showed that the incidence of ornithine transcarbamoylase activity (EC 2.1.3.3) accounted for about 35% in the particulate fraction, but that its contribution was negligible in the soluble fraction. Increasing concentrations of the irreversible inhibitor α-difluoromethylornithine (DFMO) progressively inhibited putative ODC activity with a 40% inhibition at 20 mM DFMO. Taking into consideration the incidence of ornithine transcarbamoylase activity, the total inhibition of putative ODC activity was of about 75%. Fractionation experiments permitted measurement of putative ODC activity in the nuclei- and chloroplast-enriched fractions. The assays performed on membranes and stromal fractions isolated from gradient purified chloroplasts showed that the enzyme activity was associated almost totally with the plastid membranes.
ISSN:0981-9428
1873-2690
DOI:10.1016/S0981-9428(03)00141-4