Abstract
The properties of two amylase activities which differ in their substrate specificity and subcellular location as well as a chloroplast-associated R-enzyme (debranching activity) are reported. An extrachloroplastic amylase is resolved by gel filtration chromatography into two activities of 80,000 and 40,000 daltons. Both extrachloroplastic activities hydrolyze amylopectin and shellfish glycogen and only slowly hydrolyze rabbit liver glycogen, beta-limit amylopectin, and amylose. In contrast, the major chloroplastic amylase attacks all of these glucans at comparable rates. Glucan hydrolysis by both the extrachloroplastic and chloroplastic amylase generates not only maltose but appreciable amounts of other oligosaccharides, whereas maltotetraose hydrolysis produces glucose, maltose, and maltotriose. The action patterns displayed by the amylase activities indicate that both are endoamylases, although they lack the typical Ca(2+) requirement or heat stability of seed endosperm alpha-amylases. Dithiothreitol, glutathione (oxidized or reduced), ascorbate, dehydroascorbate, and dithiothreitol plus thioredoxin have no effect on either the chloroplastic or extrachloroplastic amylase activities.The chloroplastic R-enzyme debranches amylopectin, beta-limit amylopectin, pullulan, and alpha-limit dextrins, but not rabbit liver glycogen. An increase in extinction coefficient and lambda(max) is detected when the debranched amylopectin and beta-limit amylopectin form a complex with I(2)-KI. Based on these properties, the chloroplastic R-enzyme is similar in enzymic activity to the R-enzyme observed in endosperm tissue.
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Claims 18
Claim · model-written summary
Extrachloroplastic amylase activity resolves by gel filtration into two activities of 80,000 and 40,000 daltons in spinach leaves.
- Taxon
- Spinach
Spinacia oleraceat0 - Gene
- extrachloroplastic amylasee1
- Outcome
- resolved by gel filtration chromatography into two activitiese1
- Value
- 80,000 and 40,000 daltonse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e1“An extrachloroplastic amylase is resolved by gel filtration chromatography into two activities of 80,000 and 40,000 daltons”
Claim · model-written summary
Both extrachloroplastic amylase activities hydrolyze amylopectin and shellfish glycogen in spinach leaves.
- Taxon
- SpinachSpinacia oleraceat0
- Outcome
- hydrolyze amylopectin and shellfish glycogene2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e2“Both extrachloroplastic activities hydrolyze amylopectin and shellfish glycogen”
Claim · model-written summary
Both extrachloroplastic amylase activities hydrolyze rabbit liver glycogen, beta-limit amylopectin and amylose only slowly in spinach leaves.
- Taxon
- SpinachSpinacia oleraceat0
- Outcome
- only slowly hydrolyze rabbit liver glycogen, beta-limit amylopectin, and amylosee3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e3“only slowly hydrolyze rabbit liver glycogen, beta-limit amylopectin, and amylose”
Claim · model-written summary
The major chloroplastic amylase of spinach leaves attacks all tested glucans at comparable rates.
- Taxon
- SpinachSpinacia oleraceat0
- Gene
- major chloroplastic amylasee4
- Outcome
- attacks all of these glucans at comparable ratese4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e4“the major chloroplastic amylase attacks all of these glucans at comparable rates”
Claim · model-written summary
Glucan hydrolysis by both spinach leaf amylases generates appreciable amounts of oligosaccharides besides maltose.
- Taxon
- SpinachSpinacia oleraceat0
- Outcome
- appreciable amounts of other oligosaccharidese5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e5“Glucan hydrolysis by both the extrachloroplastic and chloroplastic amylase generates not only maltose but appreciable amounts of other oligosaccharides”
Claim · model-written summary
Maltotetraose hydrolysis by spinach leaf amylases produces glucose, maltose and maltotriose.
- Taxon
- SpinachSpinacia oleraceat0
- Compound
- maltotetraosee6
- Outcome
- produces glucose, maltose, and maltotriosee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e6“whereas maltotetraose hydrolysis produces glucose, maltose, and maltotriose”
Claim · model-written summary
The action patterns indicate that both spinach leaf amylase activities are endoamylases.
- Taxon
- SpinachSpinacia oleraceat0
- Outcome
- both are endoamylasese7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e7“The action patterns displayed by the amylase activities indicate that both are endoamylases”
Claim · model-written summary
Spinach leaf amylases lack the typical Ca(2+) requirement or heat stability of seed endosperm alpha-amylases.
- Taxon
- SpinachSpinacia oleraceat0
- Outcome
- lack the typical Ca(2+) requirement or heat stabilitye0
- Comparator
- seed endosperm alpha-amylasese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e0“they lack the typical Ca(2+) requirement or heat stability of seed endosperm alpha-amylases”
Claim · model-written summary
Dithiothreitol had no effect on chloroplastic or extrachloroplastic amylase activities of spinach leaves.
- Taxon
- SpinachSpinacia oleraceat0
- Treatment
- Dithiothreitole1
- Outcome
- chloroplastic or extrachloroplastic amylase activitiese1
- Direction
- no effecte1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e1“Dithiothreitol, glutathione (oxidized or reduced), ascorbate, dehydroascorbate, and dithiothreitol plus thioredoxin have no effect on either the chloroplastic or extrachloroplastic amylase activities”
Claim · model-written summary
Glutathione (oxidized or reduced) had no effect on chloroplastic or extrachloroplastic amylase activities of spinach leaves.
- Taxon
- SpinachSpinacia oleraceat0
- Treatment
- glutathione (oxidized or reduced)e1
- Outcome
- chloroplastic or extrachloroplastic amylase activitiese1
- Direction
- no effecte1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e1“Dithiothreitol, glutathione (oxidized or reduced), ascorbate, dehydroascorbate, and dithiothreitol plus thioredoxin have no effect on either the chloroplastic or extrachloroplastic amylase activities”
Claim · model-written summary
Ascorbate had no effect on chloroplastic or extrachloroplastic amylase activities of spinach leaves.
- Taxon
- SpinachSpinacia oleraceat0
- Treatment
- ascorbatee1
- Outcome
- chloroplastic or extrachloroplastic amylase activitiese1
- Direction
- no effecte1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e1“Dithiothreitol, glutathione (oxidized or reduced), ascorbate, dehydroascorbate, and dithiothreitol plus thioredoxin have no effect on either the chloroplastic or extrachloroplastic amylase activities”
Claim · model-written summary
Dehydroascorbate had no effect on chloroplastic or extrachloroplastic amylase activities of spinach leaves.
- Taxon
- SpinachSpinacia oleraceat0
- Treatment
- dehydroascorbatee1
- Outcome
- chloroplastic or extrachloroplastic amylase activitiese1
- Direction
- no effecte1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e1“Dithiothreitol, glutathione (oxidized or reduced), ascorbate, dehydroascorbate, and dithiothreitol plus thioredoxin have no effect on either the chloroplastic or extrachloroplastic amylase activities”
Claim · model-written summary
Dithiothreitol plus thioredoxin had no effect on chloroplastic or extrachloroplastic amylase activities of spinach leaves.
- Taxon
- SpinachSpinacia oleraceat0
- Treatment
- dithiothreitol plus thioredoxine1
- Outcome
- chloroplastic or extrachloroplastic amylase activitiese1
- Direction
- no effecte1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e1“Dithiothreitol, glutathione (oxidized or reduced), ascorbate, dehydroascorbate, and dithiothreitol plus thioredoxin have no effect on either the chloroplastic or extrachloroplastic amylase activities”
Claim · model-written summary
The chloroplastic R-enzyme of spinach leaves debranches amylopectin, beta-limit amylopectin and pullulan.
- Taxon
- SpinachSpinacia oleraceat0
- Gene
- chloroplastic R-enzymee2
- Outcome
- debranches amylopectin, beta-limit amylopectin, pullulane2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e2“The chloroplastic R-enzyme debranches amylopectin, beta-limit amylopectin, pullulan, and alpha-limit dextrins, but not rabbit liver glycogen”
Claim · model-written summary
The chloroplastic R-enzyme of spinach leaves debranches alpha-limit dextrins.
- Taxon
- SpinachSpinacia oleraceat0
- Gene
- chloroplastic R-enzymee2
- Outcome
- alpha-limit dextrinse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e2“The chloroplastic R-enzyme debranches amylopectin, beta-limit amylopectin, pullulan, and alpha-limit dextrins, but not rabbit liver glycogen”
Claim · model-written summary
The chloroplastic R-enzyme of spinach leaves does not debranch rabbit liver glycogen.
- Taxon
- SpinachSpinacia oleraceat0
- Gene
- chloroplastic R-enzymee2
- Outcome
- not rabbit liver glycogene2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e2“The chloroplastic R-enzyme debranches amylopectin, beta-limit amylopectin, pullulan, and alpha-limit dextrins, but not rabbit liver glycogen”
Claim · model-written summary
An increase in extinction coefficient and lambda(max) is detected when debranched amylopectin and beta-limit amylopectin form a complex with I2-KI in spinach.
- Taxon
- SpinachSpinacia oleraceat0
- Compound
- I(2)-KIe3
- Outcome
- extinction coefficient and lambda(max)e3
- Direction
- increasee3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e3“An increase in extinction coefficient and lambda(max) is detected when the debranched amylopectin and beta-limit amylopectin form a complex with I(2)-KI”
Claim · model-written summary
The chloroplastic R-enzyme of spinach leaves is similar in enzymic activity to the R-enzyme of endosperm tissue.
- Taxon
- SpinachSpinacia oleraceat0
- Organ / stage
- endosperm tissuee4
- Gene
- chloroplastic R-enzymee4
- Outcome
- enzymic activitye4
- Direction
- similare4
- Comparator
- R-enzyme observed in endosperm tissuee4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Starch Degradation in Spinach Leaves”
e4“the chloroplastic R-enzyme is similar in enzymic activity to the R-enzyme observed in endosperm tissue”
The same questions in other papers
ascorbate · physiology: enzyme activity · Spinacia oleracea (spinach)Positive and negative results
1 in the opposite direction
- positive
thioredoxin · physiology: enzyme activity · Spinacia oleracea (spinach)Results agree
1 paper in the same direction as this paper
- no effect
1,4-dithiothreitol · physiology: enzyme activity · Spinacia oleracea (spinach)Results agree
3 papers in the same direction as this paper
- no effect
- no effect
- no effect
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.