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Information on EC 3.2.1.68 - isoamylase and Organism(s) Oryza sativa and UniProt Accession D0TZF0
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3.2.1.68 isoamylaseIUBMB Comments
Also readily hydrolyses amylopectin. Differs from EC 3.2.1.41 (pullulanase) and EC 3.2.1.142 (limit dextrinase) by its inability to hydrolyse pullulan, and by limited action on alpha-limit dextrins. Maltose is the smallest sugar it can release from an alpha-(1->6)-linkage.
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Word Map
- 3.2.1.68
-
salivary
- lipase
- amylopectin
-
hyperamylasemia
- isoenzymes
- alpha-amylase
- pancreas
- phosphorylase
- amylose
- pullulanase
-
exocrine
- abdominal
- endosperm
- dextrin
- glucans
- phytoglycogen
-
salivary-type
-
nonpancreatic
-
amylolytic
- pseudocysts
-
s-type
- beta-amylase
-
dextrinase
-
pancreatic-type
-
macroamylasemia
- amylo-1,6-glucosidase
-
extrapancreatic
-
glucanotransferase
-
phadebas
- analysis
- 4-alpha-glucanotransferase
- nutrition
- maltooligosaccharides
-
glycogenolytic
- maltotriose
-
alpha-1,4
- isomaltose
- alpha-glucans
-
waxy
-
hyperenzymemia
- glycogenin
-
granule-bound
- medicine
- food industry
- synthesis
- degradation
- detergent
The taxonomic range for the selected organisms is: Oryza sativa
The expected taxonomic range for this enzyme is: Bacteria, Eukaryota, Archaea
The expected taxonomic range for this enzyme is: Bacteria, Eukaryota, Archaea
Reaction Schemes
Synonyms
isoamylase, glycogen debranching enzyme, starch debranching enzyme, alpha-1,6-glucosidase, glycogen-debranching enzyme, isoamylase1, atisa3, isoamylase 3, isoamylase-type debranching enzyme, atisa1, 
more
topSYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
debranching enzyme
-
-
-
-
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
hydrolysis of O-glycosyl bond
hydrolysis of O-glycosyl bond
-
-
-
-
PATHWAY SOURCE
PATHWAYS
BRENDA
-
-, -, -
SYSTEMATIC NAME
IUBMB Comments
glycogen 6-alpha-D-glucanohydrolase
Also readily hydrolyses amylopectin. Differs from EC 3.2.1.41 (pullulanase) and EC 3.2.1.142 (limit dextrinase) by its inability to hydrolyse pullulan, and by limited action on alpha-limit dextrins. Maltose is the smallest sugar it can release from an alpha-(1->6)-linkage.
CAS REGISTRY NUMBER
COMMENTARY
9067-73-6
-
SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
amylose-extender amylopectin + H2O
maltose + maltooligosaccharides
O80403
-
-
-
?
beta limit dextrin + H2O
maltose + maltooligosaccharides
O80403
from maize
-
-
?
amylose-extender amylopectin + H2O
maltose + maltooligosaccharides
O80403
-
-
-
?
beta limit dextrin + H2O
maltose + maltooligosaccharides
O80403
from maize
-
-
?
beta-amylase limit dextrin + H2O
?
-
isoform ISA1 shows 71% activity compared to phosphorylase a limit dextrin. Isoform ISA3 shows 48% activity compared to phosphorylase a limit dextrin
-
-
?
phytoglycogen + H2O
?
-
short chains of DP3 and DP4 are most effectively liberated by isoform ISA1 during the short period, and with the elapse of the incubation time intermediate chains with the peak of DP6 are more significantly produced. Almost only short chains of DP3 and DP4 are found after the isoform ISA3 reaction for 5-10 min, then during the course of enzymatic reaction until 60 min a small amount of the DP5-10 chains is found
-
-
?
amylopectin + H2O
?
-
isoform ISA1 removes the wide range of chains with a degree of polymerization (DP) of 6-20 from amylopectin although the long chains of DP higher than 20 are debranched by the prolonged incubation. Isoform ISA1 shows 356% activity compared to phosphorylase a limit dextrin. Isoform ISA3 shows trace activity compared to phosphorylase a limit dextrin
-
-
?
oyster glycogen + H2O
?
-
isoform ISA1 shows 104% activity compared to phosphorylase a limit dextrin. Isoform ISA3 shows 1.5% activity compared to phosphorylase a limit dextrin
-
-
?
additional information
?
-
-
ISA1 activity plays a critical role in the stochastic process in starch synthesis in rice endosperm
-
-
?
additional information
?
-
-
recombinant isoamylase 3 does not readily hydrolyze red pullulan and amylose
-
-
?
NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
additional information
?
-
-
ISA1 activity plays a critical role in the stochastic process in starch synthesis in rice endosperm
-
-
?
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
additional information
additional information
-
amylopectin 7.2 mg/ml-1, phytoglycogen 11.9 mg/ml-1, beta-limit dextrin 13.1 mg/ml-1, glycogen 21.8 mg/ml-1
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
malfunction
-
both overexpression and loss of function of isoamylase 3 in the endosperm generated pleomorphic amyloplasts and starch granules
physiological function
physiological function
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isoamylase 3 facilitates starch metabolism and affects morphological characteristics of plastids in rice. Both overexpression and loss of function of isoamylase 3 in the endosperm generates pleomorphic amyloplasts and starch granules
physiological function
-
the isoamylase 1 is essential for amylopectin biosynthesis and starch production in rice endosperm. Overexpression of the isoamylase 2 gene brings about a dramatic reduction in kernel size in the dry seed and the transformants contain less than 50% of the starch in the kernel, while the content of soluble sugars, including maltodextrins, malto-oligosaccharides, and simple sugars, increase by about 8fold when compared with the host cultivar Kinmaze
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
510000
O80403
SDS-PAGE, heterooligomer, hetero-hexamer composed of five OsISA1 and one OsISA2
830000
O80403
homooligomer OsISA1 5 * 830000 and heterooligomer OsISA1-OsISA2 6 * 85000, HPLC gel filtration
85000
O80403
homooligomer OsISA1 5 * 830000 and heterooligomer OsISA1-OsISA2 6 * 85000, HPLC gel filtration
510000
O80403
SDS-PAGE, heterooligomer, hetero-hexamer composed of five OsISA1 and one OsISA2
SUBUNIT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
oligomer
O80403
homooligomer OsISA1 5 * 830000 and heterooligomer OsISA1-OsISA2 6 * 85000, HPLC gel filtration
oligomer
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
wild type enzyme by HitrapQ HP and TSKgel G3000SWXL column chromatography, recombinant OsISA2 by HitrapQ HP column chromatography
O80403
wild type enzyme by HitrapQ HP and TSKgel G3000SWXL column chromatography, recombinant OsISA2 by HitrapQ HP column chromatography
O80403
CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Fujita, N.; Kubo, A.; Francisco, P.B.Jr.; Nakakita, M.; Harada, K.; Minaka, N.; Nakamura, Y.
Purification, characterization, and cDNA structure of isoamylase from developing endosperm of rice
Planta
208
283-293
1999
Oryza sativa
Kawagoe, Y.; Kubo, A.; Satoh, H.; Takaiwa, F.; Nakamura, Y.
Roles of isoamylase and ADP-glucose pyrophosphorylase in starch granule synthesis in rice endosperm
Plant J.
42
164-174
2005
Oryza sativa
Utsumi, Y.; Nakamura, Y.
Structural and enzymatic characterization of the isoamylase1 homo-oligomer and the isoamylase1-isoamylase2 hetero-oligomer from rice endosperm
Planta
225
75-87
2006
Oryza sativa, Oryza sativa (O80403)
Yun, M.S.; Umemoto, T.; Kawagoe, Y.
Rice debranching enzyme isoamylase3 facilitates starch metabolism and affects plastid morphogenesis
Plant Cell Physiol.
52
1068-1082
2011
Oryza sativa
Utsumi, Y.; Utsumi, C.; Sawada, T.; Fujita, N.; Nakamura, Y.
Functional diversity of isoamylase oligomers: the ISA1 homo-oligomer is essential for amylopectin biosynthesis in rice endosperm
Plant Physiol.
156
61-77
2011
Oryza sativa
Kobayashi, T.; Sasaki, S.; Utsumi, Y.; Fujita, N.; Umeda, K.; Sawada, T.; Kubo, A.; Abe, J.; Colleoni, C.; Ball, S.; Nakamura, Y.
Comparison of chain-length preferences and glucan specificities of isoamylase-type alpha-glucan debranching enzymes from rice, Cyanobacteria, and Bacteria
PLoS ONE
11
e0157020
2016
Crocosphaera subtropica ATCC 51142, Escherichia coli, Oryza sativa, Pseudomonas amyloderamosa, Synechococcus elongatus, Synechococcus elongatus PCC7942
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