Abstract
summary Effects of divalent metal ions (Zn, Mg, Mn), metal‐ATP complexes, and pH on the activity of the plasma membrane H + ‐ATPase were investigated. Both native vesicles, isolated by sucrose gradient centrifugation, and solubilized H + ‐ATPase, purified by linear glycerol gradient centrifugation were used. Zn, as well as Mg and Mn, stimulates the activity of H + ‐ATPase. Computer calculations of equilibrium concentrations have been used to separate the effects of individual ion complexes and free ionic forms on the enzyme activity. The calculations indicated that Zn as ZnATP + serves as a substrate of the plasma membrane H + ‐ATPase. The possibility of serving as substrate depends on the Zn/ATP ratio and the pH of the medium. The native H + ‐ATPase was activated by divalent metal ions in the order of Mg > Mn > Zn at pH 6.5 and in the order of Zn > Mn > Mg at pH 5.5 for total metal ion concentrations not higher than 3.0 mM. A Zn: ATP ratio of 0.6 at pH 5.5 gave more than 100% of the Mg‐dependent ATPase activity (Mg: ATP ratio of 1, pH 5.5). By contrast, free Zn 2+ is an effective inhibitor of ATP hydrolysis and H + transport with a strong dependence upon the pH of the medium. At pH 55 a total ZnSO 4 concentration of 1 mM induced no inhibition of ATP hydrolysis, whereas at pH 6.5 the same Zn concentration decreased the activity of the native and purified H + ‐ATPase to 49% and 34% (control activity: Mg: ATP ratio of 1, no ZnSO 4 ), respectively. We show that both activation by ZnATP 2− and inhibition by free Zn 2+ of the native plasma membrane H + ‐ATPase and the partially purified enzyme were strongly affected by the pH of the medium. The results provide evidence that Zn, in combination with the pH of the cytoplasm could play a role in regulating the plasma membrane H + ‐ATPase and thus in nutrient uptake of plant systems.
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Claims 14
Claim · model-written summary
Zn stimulated H+-ATPase activity.
- Taxon
- corn
Zea mays subsp. mayst0 - Treatment
- Zne0
- Outcome
- activity of H + ‐ATPasee0
- Direction
- stimulatese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Zn, as well as Mg and Mn, stimulates the activity of H + ‐ATPase.”
t0“corn root”
Claim · model-written summary
Mg stimulated H+-ATPase activity.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- Mge0
- Outcome
- activity of H + ‐ATPasee0
- Direction
- stimulatese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Zn, as well as Mg and Mn, stimulates the activity of H + ‐ATPase.”
t0“corn root”
Claim · model-written summary
Mn stimulated H+-ATPase activity.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- Mne0
- Outcome
- activity of H + ‐ATPasee0
- Direction
- stimulatese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Zn, as well as Mg and Mn, stimulates the activity of H + ‐ATPase.”
t0“corn root”
Claim · model-written summary
Calculations indicated ZnATP+ serves as a substrate for the enzyme.
- Taxon
- cornZea mays subsp. mayst0
- Gene
- plasma membrane H + ‐ATPasee0
- Compound
- ZnATP +e0
- Outcome
- serves as a substratee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The calculations indicated that Zn as ZnATP + serves as a substrate of the plasma membrane H + ‐ATPase.”
t0“corn root”
Claim · model-written summary
At pH 6.5 native enzyme activation ranked Mg > Mn > Zn.
- Taxon
- cornZea mays subsp. mayst0
- Outcome
- Mg > Mn > Zne0
- Direction
- activatede0
- Qualifier
- pH 6.5e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The native H + ‐ATPase was activated by divalent metal ions in the order of Mg > Mn > Zn at pH 6.5”
t0“corn root”
Claim · model-written summary
At pH 5.5 native enzyme activation ranked Zn > Mn > Mg.
- Taxon
- cornZea mays subsp. mayst0
- Outcome
- Zn > Mn > Mge0
- Qualifier
- pH 5.5e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in the order of Zn > Mn > Mg at pH 5.5 for total metal ion concentrations not higher than 3.0 mM”
t0“corn root”
Claim · model-written summary
A Zn: ATP ratio of 0.6 at pH 5.5 yielded over 100% of Mg-dependent ATPase activity.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- Zn: ATP ratio of 0.6e0
- Outcome
- ATPase activitye0
- Direction
- more thane0
- Value
- 100%e0
- Comparator
- Mg: ATP ratio of 1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A Zn: ATP ratio of 0.6 at pH 5.5 gave more than 100% of the Mg‐dependent ATPase activity (Mg: ATP ratio of 1, pH 5.5)”
t0“corn root”
Claim · model-written summary
Free Zn2+ inhibited ATP hydrolysis.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- free Zn 2+e0
- Outcome
- ATP hydrolysise0
- Direction
- inhibitore0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“free Zn 2+ is an effective inhibitor of ATP hydrolysis and H + transport”
t0“corn root”
Claim · model-written summary
Free Zn2+ inhibited H+ transport.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- free Zn 2+e0
- Outcome
- H + transporte0
- Direction
- inhibitore0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“free Zn 2+ is an effective inhibitor of ATP hydrolysis and H + transport”
t0“corn root”
Claim · model-written summary
At pH 55, 1 mM ZnSO4 did not inhibit ATP hydrolysis.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- ZnSO 4 concentration of 1 mMe0
- Outcome
- ATP hydrolysise0
- Direction
- no inhibitione0
- Qualifier
- pH 55e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At pH 55 a total ZnSO 4 concentration of 1 mM induced no inhibition of ATP hydrolysis”
t0“corn root”
Claim · model-written summary
At pH 6.5, 1 mM zinc lowered native enzyme activity to 49% of control.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- Zn concentratione0
- Outcome
- activity of the native and purified H + ‐ATPasee0
- Direction
- decreasede0
- Value
- 49%e0
- Comparator
- control activity: Mg: ATP ratio of 1, no ZnSO 4e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at pH 6.5 the same Zn concentration decreased the activity of the native and purified H + ‐ATPase to 49% and 34% (control activity: Mg: ATP ratio of 1, no ZnSO 4 )”
t0“corn root”
Claim · model-written summary
At pH 6.5, 1 mM zinc lowered purified enzyme activity to 34% of control.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- Zn concentratione0
- Outcome
- activity of the native and purified H + ‐ATPasee0
- Direction
- decreasede0
- Value
- 34%e0
- Comparator
- control activity: Mg: ATP ratio of 1, no ZnSO 4e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at pH 6.5 the same Zn concentration decreased the activity of the native and purified H + ‐ATPase to 49% and 34% (control activity: Mg: ATP ratio of 1, no ZnSO 4 )”
t0“corn root”
Claim · model-written summary
pH strongly affected zinc-complex activation of native and partly purified H+-ATPase.
- Taxon
- cornZea mays subsp. mayst0
- Outcome
- activation by ZnATP 2−e0
- Setting
- pH of the mediume0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“activation by ZnATP 2− and inhibition by free Zn 2+ of the native plasma membrane H + ‐ATPase and the partially purified enzyme were strongly affected by the pH of the medium”
t0“corn root”
Claim · model-written summary
pH strongly affected free-zinc inhibition of native and partly purified H+-ATPase.
- Taxon
- cornZea mays subsp. mayst0
- Outcome
- inhibition by free Zn 2+e0
- Setting
- pH of the mediume0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“activation by ZnATP 2− and inhibition by free Zn 2+ of the native plasma membrane H + ‐ATPase and the partially purified enzyme were strongly affected by the pH of the medium”
t0“corn root”
The same questions in other papers
zinc sulfate · molecular: metabolites · Zea mays (maize)Positive and negative results
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- positive
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See all 10 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.