INVESTIGADORES
TRIPODI Karina Eva Josefina
artículos
Título:
Molecular cloning, expression and characterization of a NAD+ dependent cytosolic malate dehydrogenase (cMDH-NAD+) from Mesembryanthemum crystallinum
Autor/es:
TRIPODI, KARINA; GOMEZ-CASATI, M. E.; UTTARO, A. D.; PODESTÁ, F.
Revista:
Physiologia Plantarum
Editorial:
Scandinavian Plant Physiology Society
Referencias:
Año: 2003 vol. 117 p. 222 - 228
ISSN:
0031-9317
Resumen:
NAD+-dependent cytosolic malate dehydrogenase (MDH, E.C. 1.1.1.37) from leaves of Mesembryanthemum crystallinum in the Crassulacean Acid Metabolism (CAM) mode was cloned, expressed in E. coli and characterized. The recombinant enzyme had a subunit molecular mass of 39.5 kDa and was recognized by antibodies raised against the cytosolic MDH from Ananas comosus. Its activity showed a maximum in the pH range of 7.5-9.5. The purified MDH is highly but not completely specific for oxaloacetate as indicated by a low activity using various other alfa-cetoacids as substrates. The sequence data, subunit mass and immunoreactivity sugest that the MDH that has been cloned and characterized corresponds to the citosolic isoform. Yet, the biochemistry of this enzyme comparative with the only other CAM plant cytosolic MDH characterized so far (that of pineapple) hints at a distint isoform being expressed in M. crystallinum leaves.
