Information on EC 3.2.1.B8 - malto-alpha-amylase (reducing end)

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The expected taxonomic range for this enzyme is: Bacteria, Archaea

EC NUMBER
COMMENTARY hide
3.2.1.B8
preliminary BRENDA-supplied EC number
RECOMMENDED NAME
GeneOntology No.
malto-alpha-amylase (reducing end)
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REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
hydrolysis of (1->4)-alpha-D-glucosidic linkages in polysaccharides so as to remove successive alpha-maltose residues from the reducing ends of the chains
show the reaction diagram
SYSTEMATIC NAME
IUBMB Comments
glucan 1,4-alpha-maltohydrolase (reducing end)
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ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
strain 168, gene yvdF
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-
Manually annotated by BRENDA team
strain 168, gene yvdF
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-
Manually annotated by BRENDA team
gene malZ
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Manually annotated by BRENDA team
gene TM1835; gene TM1835
UniProt
Manually annotated by BRENDA team
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
4-nitrophenyl-alpha-pentaoside + H2O
maltopentaose + 4-nitrophenol
show the reaction diagram
-
further hydrolysis of maltopentaose by TMG
-
?
acarbose + 2 H2O
acarviosine + 2 D-glucose
show the reaction diagram
alpha-cyclodextrin + H2O
maltose + D-glucose
show the reaction diagram
beta-cyclodextrin + H2O
maltose + D-glucose
show the reaction diagram
cycloamylose + H2O
maltose + D-glucose
show the reaction diagram
-
-
primary products
-
?
gamma-cyclodextrin + H2O
maltose + D-glucose
show the reaction diagram
linear maltoheptaose + H2O
maltose + D-glucose
show the reaction diagram
-
SMMA preferentially hydrolyzed the first and second glycosidic bonds from the reducing end
primary products
-
?
linear maltohexaose + H2O
maltose + D-glucose
show the reaction diagram
-
best substrate
primary products
-
?
linear maltooligosaccharide + H2O
maltose + D-glucose
show the reaction diagram
-
maximal activity of SMMA toward G6, but almost no activity toward G3
primary products
-
?
malto-heptaose + H2O
maltose + D-glucose
show the reaction diagram
malto-hexaose + H2O
maltose + D-glucose
show the reaction diagram
-
-
-
?
malto-pentaose + H2O
maltose + D-glucose
show the reaction diagram
-
-
-
?
malto-tetraose + H2O
maltose + D-glucose
show the reaction diagram
malto-triose + H2O
maltose + D-glucose
show the reaction diagram
maltoheptaose + H2O
maltose + D-glucose
show the reaction diagram
-
-
-
?
maltohexaose + H2O
maltose + D-glucose
show the reaction diagram
-
-
-
?
maltopentaose + H2O
maltose + D-glucose
show the reaction diagram
-
-
-
?
maltotetraose + H2O
maltose + D-glucose
show the reaction diagram
-
-
-
?
maltotriose + H2O
maltose + D-glucose
show the reaction diagram
-
-
-
?
pullulan + H2O
panose + D-glucose
show the reaction diagram
-
-
-
-
?
soluble starch + H2O
maltose + D-glucose
show the reaction diagram
-
-
-
?
starch + H2O
maltose + D-glucose
show the reaction diagram
-
-
primary products
-
?
additional information
?
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
acarbose + 2 H2O
acarviosine + 2 D-glucose
show the reaction diagram
alpha-cyclodextrin + H2O
maltose + D-glucose
show the reaction diagram
beta-cyclodextrin + H2O
maltose + D-glucose
show the reaction diagram
cycloamylose + H2O
maltose + D-glucose
show the reaction diagram
-
-
primary products
-
?
gamma-cyclodextrin + H2O
maltose + D-glucose
show the reaction diagram
linear maltoheptaose + H2O
maltose + D-glucose
show the reaction diagram
-
SMMA preferentially hydrolyzed the first and second glycosidic bonds from the reducing end
primary products
-
?
linear maltohexaose + H2O
maltose + D-glucose
show the reaction diagram
-
best substrate
primary products
-
?
linear maltooligosaccharide + H2O
maltose + D-glucose
show the reaction diagram
-
maximal activity of SMMA toward G6, but almost no activity toward G3
primary products
-
?
maltoheptaose + H2O
maltose + D-glucose
show the reaction diagram
Q9X2F4
-
-
-
?
maltohexaose + H2O
maltose + D-glucose
show the reaction diagram
Q9X2F4
-
-
-
?
maltopentaose + H2O
maltose + D-glucose
show the reaction diagram
Q9X2F4
-
-
-
?
maltotetraose + H2O
maltose + D-glucose
show the reaction diagram
Q9X2F4
-
-
-
?
maltotriose + H2O
maltose + D-glucose
show the reaction diagram
Q9X2F4
-
-
-
?
pullulan + H2O
panose + D-glucose
show the reaction diagram
-
-
-
-
?
soluble starch + H2O
maltose + D-glucose
show the reaction diagram
Q9X2F4
-
-
-
?
starch + H2O
maltose + D-glucose
show the reaction diagram
-
-
primary products
-
?
additional information
?
-
Q9X2F4
TMG is an exo-acting glucosidase possessing the characteristics of both CD-/pullulan hydrolyzing enzyme and alpha-glucosidase. It hydrolyzes various maltodextrins including maltotriose to maltoheptaose and cyclomaltodextrins to mainly glucose and maltose, but it cannot hydrolyze pullulan, but acarbose
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-
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INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
no inhibition by EGTA and EDTA
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KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
2.26
4-nitrophenyl alpha-maltopentaoside
pH 6.5, 85C, recombinant enzyme
14.53
beta-cyclodextrin
pH 6.5, 85C, recombinant enzyme
7.41
maltoheptaose
pH 6.5, 85C, recombinant enzyme
7.77
maltohexaose
pH 6.5, 85C, recombinant enzyme
9.95
maltopentaose
pH 6.5, 85C, recombinant enzyme
11.84
maltotetraose
pH 6.5, 85C, recombinant enzyme
20.64
maltotriose
pH 6.5, 85C, recombinant enzyme
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
16.28
4-nitrophenyl alpha-maltopentaoside
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
1.37
beta-cyclodextrin
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
4.09
maltoheptaose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
4.56
maltohexaose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
5.18
maltopentaose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
4.34
maltotetraose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
3.2
maltotriose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
7.2
4-nitrophenyl alpha-maltopentaoside
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
27609
0.094
beta-cyclodextrin
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
302
0.55
maltoheptaose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
323
0.59
maltohexaose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
314
0.52
maltopentaose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
272
0.37
maltotetraose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
269
0.16
maltotriose
Thermotoga maritima MSB8
Q9X2F4
pH 6.5, 85C, recombinant enzyme
188
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.24
purified recombinant enzyme, substrate soluble starch
1.13
-
crude recombinant enzyme in Escherichia coli cell extract, substrate gamma-cyclodextrin
4.85
purified recombinant enzyme, substrate beta-cyclodextrin
18.6
purified recombinant enzyme, substrate maltotriose
39.3
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purified recombinant enzyme
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
3.5 - 5
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activity range, 52% and 90% of maximal activity at pH 3.5 and pH 4.0, respectively
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
82500
-
2 * 82500, recombinant [Leu-Glu-(His)6]-tagged enzyme, SDS-PAGE, 2 * 83600, about, recombinant [Leu-Glu-(His)6]-tagged enzyme, mass spectrometry
83600
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2 * 82500, recombinant [Leu-Glu-(His)6]-tagged enzyme, SDS-PAGE, 2 * 83600, about, recombinant [Leu-Glu-(His)6]-tagged enzyme, mass spectrometry
173000
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recombinant tagged enzyme, sedimentation equilibrium analytical ultracentrifugation
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
dimer
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2 * 82500, recombinant [Leu-Glu-(His)6]-tagged enzyme, SDS-PAGE, 2 * 83600, about, recombinant [Leu-Glu-(His)6]-tagged enzyme, mass spectrometry
additional information
-
in SMMA, non-polar side chains at 357W, 408W, 449Y, 451W, 463Y, 490Y, 501Y, 517Y 519Y, 529Y, 593W, and 608Y are located at the termini of alpha-helixes and beta-sheets contributing to the extreme thermostability of the enzyme
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5 - 10
-
purified recombinant SMMA shows excellent stability over the pH range of 5.0-10, when incubated at 37 8C for 24 h
710128
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
20 - 130
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differential scanning calorimetric analysis of SMMA, profile, overview
100 - 109
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the enzyme is extremely thermostable, with a temperature optimum of 100C and a melting temperature of 109C
additional information
-
in SMMA, non-polar side chains at 357W, 408W, 449Y, 451W, 463Y, 490Y, 501Y, 517Y 519Y, 529Y, 593W, and 608Y are located at the termini of alpha-helixes and beta-sheets contributing to the extreme thermostability of the enzyme
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
recombinant His-tagged SMMA 34.8fold from Escherichia coli by heat treatment at 70C for 20 min, and nickel affinity chromatography, to homogeneity
-
recombinant TMG 18.2fold from Escherichia coli strain MC1061 by heat treatment, hydrophobic interaction and anion exchange chromatography
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expression as malZ-yvdF fusion protein in Escherichia coli strain JT1
gene TM1835, expression in Escherichia coli strain MC1061
phylogenetic tree, overexpression of C-terminally [Leu-Glu-(His)6]-tagged SMMA in Escherichia coli
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ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
food industry
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the enzyme might be of potential value in the food and starch industries due to its extreme thermostability