Premium
Characterization of the plasmalemma ATPase activity from roots of Plantago major ssp. pleiosperma , purified by the two‐phase partitioning method
Author(s) -
Staal Marten,
Hommels Cees,
Kuiper Daan
Publication year - 1987
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1987.tb02843.x
Subject(s) - atpase , chemistry , stimulation , enzyme , chromatography , hydrolysis , biochemistry , plantago , polyethylene glycol , biology , botany , neuroscience
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 murker enzymes proved the purity of the plasmalemma fraction. The ATPase activity was characterized by determining its sensitivity to anions, cations and inhibitors. The Mg 2+ ‐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 m M MgSO 4 ). The plasmalemma preparations hydrolyzed preferentially ATP (in the presence of Mg 2+ ), although they were less specific for ATP at pH 7.5 than at pH 6.75. The Cl − ‐ stimulated ATPase 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.