Abstract
Cytoplasmic fructose-1,6-bisphosphatase has been purified from spinach leaves to apparent homogeneity. The enzyme is a tetramer of molecular weight about 130,000. At pH 7.5, the Km for fructose 1.6-bisphosphate was 2.5 micron, and for MgCl2 0.13 mM; the enzyme was specific for fructose 1,6-bisphosphate. Saturation with Mg2+ was achieved with lower concentrations at pH 8 than at pH 7. AMP and high concentrations of fructose 1,6-bisphosphate inhibited enzyme activity. Ammonium sulfate relieved the latter inhibition but was itself inhibitory when substrate concentrations were low. Acetylation studies demonstrated that the AMP regulatory site was distinct from the catalytic site. Cytoplasmic fructose-1,6-bisphosphatase may contribute to the regulation of sucrose biosynthesis in plant leaves.
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Claims 12
Claim · model-written summary
Cytoplasmic fructose-1,6-bisphosphatase was purified from spinach leaves to apparent homogeneity.
- Taxon
- spinach
Spinacia oleraceae0 - Organ / stage
- leavese0
- Gene
- Cytoplasmic fructose-1,6-bisphosphatasee0
- Outcome
- purified from spinach leaves to apparent homogeneitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cytoplasmic fructose-1,6-bisphosphatase has been purified from spinach leaves to apparent homogeneity”
Claim · model-written summary
The spinach enzyme is a tetramer of molecular weight about 130,000.
- Taxon
- spinachSpinacia oleraceat0
- Gene
- cytoplasmic fructose-1,6-bisphosphataset0
- Outcome
- tetramer of molecular weighte0
- Value
- about 130,000e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“The enzyme is a tetramer of molecular weight about 130,000”
Claim · model-written summary
At pH 7.5, Km for fructose 1.6-bisphosphate was 2.5 micron.
- Taxon
- spinachSpinacia oleraceat0
- Gene
- cytoplasmic fructose-1,6-bisphosphataset0
- Outcome
- Km for fructose 1.6-bisphosphatee0
- Value
- 2.5 microne0
- Qualifier
- At pH 7.5e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“At pH 7.5, the Km for fructose 1.6-bisphosphate was 2.5 micron”
Claim · model-written summary
At pH 7.5, Km for MgCl2 was 0.13 mM.
- Taxon
- spinachSpinacia oleraceat0
- Gene
- cytoplasmic fructose-1,6-bisphosphataset0
- Outcome
- for MgCl2e0
- Value
- 0.13 mMe0
- Qualifier
- At pH 7.5e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“At pH 7.5, the Km for fructose 1.6-bisphosphate was 2.5 micron, and for MgCl2 0.13 mM”
Claim · model-written summary
The enzyme was specific for fructose 1,6-bisphosphate.
- Taxon
- spinachSpinacia oleraceat0
- Gene
- cytoplasmic fructose-1,6-bisphosphataset0
- Outcome
- specific for fructose 1,6-bisphosphatee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“the enzyme was specific for fructose 1,6-bisphosphate”
Claim · model-written summary
Mg2+ saturation required lower concentrations at pH 8 than at pH 7.
- Taxon
- spinachSpinacia oleraceat0
- Gene
- cytoplasmic fructose-1,6-bisphosphataset0
- Outcome
- Saturation with Mg2+e0
- Direction
- lowere0
- Qualifier
- at pH 8e0
- Comparator
- at pH 7e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“Saturation with Mg2+ was achieved with lower concentrations at pH 8 than at pH 7”
Claim · model-written summary
AMP inhibited enzyme activity.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- AMPe0
- Outcome
- enzyme activitye0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“AMP and high concentrations of fructose 1,6-bisphosphate inhibited enzyme activity”
Claim · model-written summary
High fructose 1,6-bisphosphate concentrations inhibited enzyme activity.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- high concentrations of fructose 1,6-bisphosphatee0
- Outcome
- enzyme activitye0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“AMP and high concentrations of fructose 1,6-bisphosphate inhibited enzyme activity”
Claim · model-written summary
Ammonium sulfate relieved inhibition by high fructose 1,6-bisphosphate concentrations.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- Ammonium sulfatee0
- Outcome
- the latter inhibitione0
- Direction
- relievede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“Ammonium sulfate relieved the latter inhibition”
Claim · model-written summary
Ammonium sulfate inhibited activity when substrate concentrations were low.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- Ammonium sulfatee0
- Outcome
- itself inhibitorye0
- Direction
- inhibitorye0
- Qualifier
- when substrate concentrations were lowe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“Ammonium sulfate relieved the latter inhibition but was itself inhibitory when substrate concentrations were low”
Claim · model-written summary
Acetylation studies indicated distinct AMP regulatory and catalytic sites.
- Taxon
- spinachSpinacia oleraceat0
- Gene
- cytoplasmic fructose-1,6-bisphosphataset0
- Outcome
- AMP regulatory site was distinct from the catalytic sitee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“Acetylation studies demonstrated that the AMP regulatory site was distinct from the catalytic site”
Claim · model-written summary
The enzyme may contribute to regulation of sucrose biosynthesis in leaves.
- Taxon
- spinachSpinacia oleraceat0
- Organ / stage
- leavese0
- Gene
- Cytoplasmic fructose-1,6-bisphosphatasee0
- Outcome
- regulation of sucrose biosynthesise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“spinach leaf cytoplasmic fructose-1,6-bisphosphatase”
e0“Cytoplasmic fructose-1,6-bisphosphatase may contribute to the regulation of sucrose biosynthesis in plant leaves”