Betaine aldehyde dehydrogenase from spinach leaves: purification, in vitro translation of the mRNA, and regulation by salinity.
|
| 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.
|
|---|---|
| Authors | E A Weretilnyk, A D Hanson |
| Journal | Archives of biochemistry and biophysics (Arch Biochem Biophys) Vol. 271 Issue 1 Pg. 56-63 (May 15 1989) ISSN: 0003-9861 [Print] United States |
| PMID | 2712575 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.) |
| Chemical References |
|
| Topics |
|
Join CureHunter, for free Research Interface BASIC access!
Realize the full power of the drug-disease research graph!