CEFOBI   05405
CENTRO DE ESTUDIOS FOTOSINTETICOS Y BIOQUIMICOS
Unidad Ejecutora - UE
artículos
Título:
Cloning, Expression, Purification And Physical And Kinetic Characterization Of The Phosphoenolpyruvate Carboxylase From Orange (Citrus sinensis Osbeck var. Valencia) Fruit Juice Sacs.
Autor/es:
PEROTTI, VALERIA. E.; FIGUEROA, CARLOS M.; ANDREO, CARLOS S.; IGLESIAS, ALBERTO A.; PODESTÁ, FLORENCIO E.
Revista:
PLANT SCIENCE
Editorial:
ELSEVIER IRELAND LTD
Referencias:
Lugar: Amsterdam; Año: 2010
ISSN:
0168-9452
Resumen:
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Phosphoenolpyruvate (PEP) carboxylase (PEPCase) from orange fruit juice
sacs has been cloned and heterogously expressed in high yield. The purified
recombinant enzyme displays properties typical of plant PEPCase, including
activation by sugar phosphates and inhibition by malate and citrate. Malate
inhibition is weak in the physiological pH range, and the enzyme is also poorly
affected by Glu and Asp, known inhibitors of C3 plants PEPCases. However,
it is strongly inhibited by citrate. Orange fruit PEPCase phosphorylation by
mammalian protein kinase A decreased inhibition by malate. The enzyme presents
an unusual high molecular mass in the absence of PEP, while in its presence it
displays a more common tetrameric arrangement. The overall properties of the
enzyme suggest that it is suited for organic acid synthesis and NADH
reoxidation in the mature fruit. The present study provides the first analysis
of a recombinant fruit PEPCase.