| Autor: |
Staal, Marten, Hommels, Cees, Kuiper, Daan |
| Předmět: |
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| Zdroj: |
Physiologia Plantarum; Jul87, Vol. 70 Issue 3, p461-466, 6p |
| Abstrakt: |
A purified plasmalemma preparation from roots of Plantago major L. ssp. pleiosperma (Pilger) was obtained by the two-phase partitioning method, using 6.5% (w/w) of Dextran T-500 and polyethylene glycol 3350, respectively. The distribution of marker enzymes proved the purity of the plasmalemma fraction. The ATPase activity was characterized by determining its sensitivity to anions, cations and inhibitors. The Mg2+-dependent ATPase activity peaked at pH 7.25. K+-stimulation at pH 6.75, and the Cl--stimulation both at pH 6.75 and 7.5 (all in the presence of 3 mM MgSO4). The plasmalemma preparations hydrolyzed preferentially ATP (in the presence of Mg2+), although they were less specific for ATP at pH 7.5 than at pH 6.75. The Cl-- stimulated ATFase is probably associated with and located on the plasmalemma. The question if the Cl--stimulated activity is due to an ATPase distinct from the classical K+-stimulated ATPase is considered. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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