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Arch Biochem Biophys. 1989 May 15;271(1):56-63.

Betaine aldehyde dehydrogenase from spinach leaves: purification, in vitro translation of the mRNA, and regulation by salinity.

Author information

1
MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing 48824.

Abstract

Spinach (Spinacia oleracea L.) leaves contain a nuclear-encoded chloroplastic betaine aldehyde dehydrogenase (EC 1.2.1.8) which is induced several-fold by salinization. Betaine aldehyde dehydrogenase was purified 2400-fold to homogeneity with an overall yield of 14%. The procedure included fractional precipitation with ammonium sulfate, followed by ion-exchange, hydrophobic interaction, and hydroxyapatite chromatography in open columns, and ion-exchange and hydrophobic interaction chromatography in a fast-protein liquid chromatography system. The betaine aldehyde dehydrogenase had a pI of 5.65, and a broad pH optimum between 7.5 and 9.5. The Km values for NAD+ and NADP+ were 20 and 320 microM, respectively; the Vmax of the reaction with NADP+ was 75% of that with NAD+. The native enzyme is a dimer with subunits of Mr 63,000. Highly specific antiserum was raised against the native enzyme, and was used in conjunction with cell-free translation of leaf poly(A)+ RNA to show (a) that betaine aldehyde dehydrogenase is synthesized as a precursor of Mr 1200 higher than the mature polypeptide, and (b) that both chronic salt stress and salt shock provoke a several-fold increase in the level of translatable message for the enzyme.

PMID:
2712575
DOI:
10.1016/0003-9861(89)90255-5
[Indexed for MEDLINE]

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