Abstract
Photophosphorylating activity of chloroplasts rapidly prepared from preilluminated spinach leaves was higher than the activity of chlorplasts from leaves kept in the dark. Higher Vmax values were obtained with the former when either ADP or Pi concentrations were varied. The rate of decay of the in vivo light-activated Mg2+-ATPase was highly dependent on temperature, increasing with it. At 0 degree C it was stable for 40 min or more. The decay at 25 degrees C was prevented by 5 mM ATP or 50 mM dithioerythritol while ADP or Pi did not affect it. Gramicidin or iodosobenzoate induced a very rapid decay even at 0 degree C. Coupling factor 1 with a manifest and stable Ca2+-ATPase activity was solubilized from chloroplasts activated by light in vivo. Incubation of chloroplasts from preilluminated leaves with N-[3H]ethylmaleimide resulted in an inhibition of Ca2+-ATPase activity and in the incorporation of radioactivity into the gamma subunit of coupling factor 1 that was larger than that of chloroplasts from leaves kept in the dark. The results show that activation in vivo of the proton ATPase was manifested by higher phosphorylating and Mg2+-ATPase activities and requires both an electrochemical proton gradient and a redox change of at least one disulfide bond of its gamma subunit.
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Claims 14
Claim · model-written summary
Preillumination increased spinach chloroplast photophosphorylating activity relative to dark leaves.
- Taxon
- spinach
Spinacia oleraceae0 - Treatment
- preilluminatede0
- Outcome
- Photophosphorylating activitye0
- Direction
- highere0
- Comparator
- leaves kept in the darke0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Photophosphorylating activity of chloroplasts rapidly prepared from preilluminated spinach leaves was higher than the activity of chlorplasts from leaves kept in the dark.”
Claim · model-written summary
Preilluminated chloroplasts had higher Vmax with ADP or Pi variation.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- ADP or Pi concentrations were variede0
- Outcome
- Vmax valuese0
- Direction
- Highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Higher Vmax values were obtained with the former when either ADP or Pi concentrations were varied.”
t0“spinach leaves”
Claim · model-written summary
Decay of light-activated Mg2+-ATPase increased with temperature.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- temperaturee0
- Gene
- Mg2+-ATPasee0
- Outcome
- rate of decaye0
- Direction
- increasinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The rate of decay of the in vivo light-activated Mg2+-ATPase was highly dependent on temperature, increasing with it.”
t0“spinach leaves”
Claim · model-written summary
Light-activated Mg2+-ATPase was stable for at least 40 minutes at 0°C.
- Taxon
- spinachSpinacia oleraceat0
- Outcome
- stablee0
- Value
- 40 min or moree0
- Qualifier
- At 0 degree Ce0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 0 degree C it was stable for 40 min or more.”
t0“spinach leaves”
Claim · model-written summary
ATP prevented decay at 25°C.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- 5 mM ATPe0
- Outcome
- decay at 25 degrees Ce0
- Direction
- preventede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The decay at 25 degrees C was prevented by 5 mM ATP or 50 mM dithioerythritol while ADP or Pi did not affect it.”
t0“spinach leaves”
Claim · model-written summary
Dithioerythritol prevented decay at 25°C.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- 50 mM dithioerythritole0
- Outcome
- decay at 25 degrees Ce0
- Direction
- preventede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The decay at 25 degrees C was prevented by 5 mM ATP or 50 mM dithioerythritol while ADP or Pi did not affect it.”
t0“spinach leaves”
Claim · model-written summary
ADP did not affect decay at 25°C.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- ADPe0
- Outcome
- decay at 25 degrees Ce0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The decay at 25 degrees C was prevented by 5 mM ATP or 50 mM dithioerythritol while ADP or Pi did not affect it.”
t0“spinach leaves”
Claim · model-written summary
Pi did not affect decay at 25°C.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- Pie0
- Outcome
- decay at 25 degrees Ce0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The decay at 25 degrees C was prevented by 5 mM ATP or 50 mM dithioerythritol while ADP or Pi did not affect it.”
t0“spinach leaves”
Claim · model-written summary
Gramicidin induced rapid decay even at 0°C.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- Gramicidine0
- Outcome
- decaye0
- Direction
- very rapide0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Gramicidin or iodosobenzoate induced a very rapid decay even at 0 degree C.”
t0“spinach leaves”
Claim · model-written summary
Iodosobenzoate induced rapid decay even at 0°C.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- iodosobenzoatee0
- Outcome
- decaye0
- Direction
- very rapide0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Gramicidin or iodosobenzoate induced a very rapid decay even at 0 degree C.”
t0“spinach leaves”
Claim · model-written summary
Coupling factor 1 with stable Ca2+-ATPase activity was solubilized from light-activated chloroplasts.
- Taxon
- spinachSpinacia oleraceat0
- Gene
- Coupling factor 1e0
- Outcome
- manifest and stable Ca2+-ATPase activitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Coupling factor 1 with a manifest and stable Ca2+-ATPase activity was solubilized from chloroplasts activated by light in vivo.”
t0“spinach leaves”
Claim · model-written summary
N-[3H]ethylmaleimide inhibited Ca2+-ATPase activity.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- N-[3H]ethylmaleimidee0
- Outcome
- Ca2+-ATPase activitye0
- Direction
- inhibitione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Incubation of chloroplasts from preilluminated leaves with N-[3H]ethylmaleimide resulted in an inhibition of Ca2+-ATPase activity and in the incorporation of radioactivity into the gamma subunit of coupling factor 1 that was larger than that of chloroplasts from leaves kept in the dark.”
t0“spinach leaves”
Claim · model-written summary
N-[3H]ethylmaleimide incorporation into the gamma subunit was greater in preilluminated than dark leaves.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- preilluminated leavese0
- Outcome
- incorporation of radioactivity into the gamma subunit of coupling factor 1e0
- Direction
- largere0
- Comparator
- leaves kept in the darke0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Incubation of chloroplasts from preilluminated leaves with N-[3H]ethylmaleimide resulted in an inhibition of Ca2+-ATPase activity and in the incorporation of radioactivity into the gamma subunit of coupling factor 1 that was larger than that of chloroplasts from leaves kept in the dark.”
t0“spinach leaves”
Claim · model-written summary
The authors infer that in vivo ATPase activation requires a proton gradient and a redox change.
- Taxon
- spinachSpinacia oleraceat0
- Outcome
- activation in vivo of the proton ATPasee0
- Qualifier
- an electrochemical proton gradient and a redox change of at least one disulfide bond of its gamma subunite0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The results show that activation in vivo of the proton ATPase was manifested by higher phosphorylating and Mg2+-ATPase activities and requires both an electrochemical proton gradient and a redox change of at least one disulfide bond of its gamma subunit.”
t0“spinach leaves”
The same questions in other papers
ATP · disease · Spinacia oleracea (spinach)Results agree
1 paper in the same direction as this paper
- positive
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.