Information on EC 3.2.1.2 - beta-amylase

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

EC NUMBER
COMMENTARY hide
3.2.1.2
-
RECOMMENDED NAME
GeneOntology No.
beta-amylase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
Hydrolysis of (1->4)-alpha-D-glucosidic linkages in polysaccharides so as to remove successive maltose units from the non-reducing ends of the chains
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
hydrolysis of O-glycosyl bond
-
-
exohydrolysis
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Metabolic pathways
-
-
Starch and sucrose metabolism
-
-
starch degradation
-
-
starch degradation I
-
-
starch degradation II
-
-
SYSTEMATIC NAME
IUBMB Comments
4-alpha-D-glucan maltohydrolase
Acts on starch, glycogen and related polysaccharides and oligosaccharides producing beta-maltose by an inversion. The term 'beta'' relates to the initial anomeric configuration of the free sugar group released and not to the configuration of the linkage hydrolysed.
CAS REGISTRY NUMBER
COMMENTARY hide
9000-91-3
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
strain 45
-
-
Manually annotated by BRENDA team
Bacillus circulans NCIMB 11033
-
UniProt
Manually annotated by BRENDA team
strain B6
-
-
Manually annotated by BRENDA team
precursor; strain DSM319
SwissProt
Manually annotated by BRENDA team
hedge bindweed, collected in Leuven in winter
SwissProt
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
pearl millet, several cultivars, overview
-
-
Manually annotated by BRENDA team
tuberous-rooted chervil
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
Debaryomyces sp.
-
-
-
Manually annotated by BRENDA team
Dioscorea batatus
cultivar ichoimo
-
-
Manually annotated by BRENDA team
Thunb.
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
UniProt
Manually annotated by BRENDA team
isolated from soil sample from a salt lake obtained from Yuncheng, China
-
-
Manually annotated by BRENDA team
17 Hordeum species, some with several suspecies, overview
-
-
Manually annotated by BRENDA team
Linn. cv. Keitt
-
-
Manually annotated by BRENDA team
cv. Nanicao
SwissProt
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
Paenibacillus polymyxa No. 26-1
No. 26-1
-
-
Manually annotated by BRENDA team
Paenibacillus polymyxa No. 72
No. 72
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
UniProt
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
Sorghum sp.
strain RR96
-
-
Manually annotated by BRENDA team
strain RR96
-
-
Manually annotated by BRENDA team
-
UniProt
Manually annotated by BRENDA team
-
UniProt
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
strain CECT1690, the perfect state of Phaffia rhodozyma
-
-
Manually annotated by BRENDA team
strain CECT1690, the perfect state of Phaffia rhodozyma
-
-
Manually annotated by BRENDA team
-
-
-
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-D-galactoside + H2O
4-nitrophenol + D-galactose
show the reaction diagram
-
-
-
?
4-nitrophenyl alpha-maltopyranoside + H2O
4-nitrophenol + alpha-maltopyranose
show the reaction diagram
-
-
-
?
4-nitrophenyl maltopentaose + H2O
4-nitrophenol + maltopentaose
show the reaction diagram
-
-
-
?
4-nitrophenyl-maltoheptaoside + H2O
?
show the reaction diagram
-
-
-
-
?
4-nitrophenyl-maltopentaoside + H2O
?
show the reaction diagram
-
-
-
-
?
alpha-glucan + H2O
?
show the reaction diagram
-
-
-
?
amylopectin + H2O
?
show the reaction diagram
amylopectin + H2O
beta-maltose + ?
show the reaction diagram
amylopectin + H2O
maltose + ?
show the reaction diagram
amylose + H2O
?
show the reaction diagram
amylose + H2O
beta-maltose
show the reaction diagram
amylose + H2O
maltose
show the reaction diagram
Sorghum sp.
-
from starch
-
-
?
amylose + H2O
maltose + ?
show the reaction diagram
catalyzes the release of maltose residues, less good substrate than starch and amylopectin
-
-
?
dextrin + H2O
?
show the reaction diagram
glycogen + H2O
?
show the reaction diagram
glycogen + H2O
beta-maltose
show the reaction diagram
glycogen + H2O
maltose + ?
show the reaction diagram
maltal + H2O
2-deoxymaltose
show the reaction diagram
-
-
-
?
maltodextrin + H2O
maltose
show the reaction diagram
-
maltodextrins with chain length from 9 to 198 glucose residues
and very small amounts of glucose and maltotriose
?
maltoheptaose + H2O
?
show the reaction diagram
maltoheptaose + H2O
maltose
show the reaction diagram
-
the exo-type enzyme can catalyze the successive liberation of beta-maltose from the nonreducing ends of alpha-1,4-linked glucopyranosyl polymers. A phenomenon called multiple or repetitive attack is observed where the enzyme releases several maltose molecules in a single enzyme-substrate complex. The multiple attack action needs the force of enzyme sliding on the substrate. In addition, it is important for the multiple attack that the enzyme and substrate have the characteristics of a stable productive substrate-enzyme complex through a hydrogen bond between the nonreducing end of the substrate and the carboxyl residue of the enzyme
-
-
?
maltohexaose + H2O
?
show the reaction diagram
maltooligosaccharide + H2O
?
show the reaction diagram
-
beta-amylase hydrolyzes maltooligosaccharides more readily as their degree of polymerization increases, this being strongest for maltooligosaccharides larger than 13 glucose residues and very weakly for maltotriose, exo-hydrolase that releases beta-maltose from the non-reducing end of alpha-1,4-linked poly- and oligoglucans until the first alpha-1,6-branching point along the substrate molecule is encountered
-
-
?
maltopentaose + H2O
2 maltose + D-glucose
show the reaction diagram
the enzyme displays dual hydrolysis activity toward alpha-1,4- and alpha-1,6-glycosidic linkages, the catalytic efficiency of 6-O-maltosyl-beta-cyclodextrin is 16fold higher than that of maltotriose. Compared to the kcat/Km value toward maltotriose, the values for longer substrates such as maltotetraose and maltopentaose are negligible
-
-
?
maltopentaose + H2O
?
show the reaction diagram
maltopentaose + H2O
maltose
show the reaction diagram
-
substrate/product binding structure, sugar subsite conformations, overview
-
-
?
maltopentose + H2O
?
show the reaction diagram
maltose + H2O
?
show the reaction diagram
the enzyme is specific for short alpha-glucans. Similar responses to maltose, glycogen, and starch but not to pullulan
-
-
?
maltotetraose + H2O
2 maltose
show the reaction diagram
maltotetraose + H2O
?
show the reaction diagram
maltotriose + H2O
?
show the reaction diagram
-
very poor substrate
-
-
?
maltotriose + H2O
maltose + D-glucose
show the reaction diagram
p-nitrophenyl-alpha-D-glucopyranoside + H2O
p-nitrophenol + glucose
show the reaction diagram
-
-
-
-
?
p-nitrophenylmaltopentaoside + H2O
?
show the reaction diagram
p-nitrophenylmaltopentaoside + H2O
p-nitrophenol + maltopentaose
show the reaction diagram
catalyzes the release of p-nitrophenol, specific substrate
-
-
?
pullulan + H2O
?
show the reaction diagram
-
-
-
-
?
soluble starch + H2O
?
show the reaction diagram
soluble starch + H2O
maltose + ?
show the reaction diagram
starch + H2O
?
show the reaction diagram
starch + H2O
beta-maltose
show the reaction diagram
starch + H2O
beta-maltose + ?
show the reaction diagram
-
-
-
-
?
starch + H2O
maltose
show the reaction diagram
starch + H2O
maltose + ?
show the reaction diagram
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
amylopectin + H2O
beta-maltose + ?
show the reaction diagram
-
-
-
-
?
amylopectin + H2O
maltose + ?
show the reaction diagram
amylose + H2O
maltose
show the reaction diagram
Sorghum sp.
-
from starch
-
-
?
maltotetraose + H2O
?
show the reaction diagram
-
-
-
-
?
starch + H2O
?
show the reaction diagram
starch + H2O
beta-maltose
show the reaction diagram
starch + H2O
maltose
show the reaction diagram
additional information
?
-
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
2-mercaptoethanol
-
activates
BaCl2
-
1 mM, activates
CaCl2
-
1 mM, activates
CoCl2
-
1 mM, activates
cysteine
-
activates
dithiothreitol
-
activates
MnCl2
-
1 mM, activates
SrCl2
-
1 mM, activates
additional information
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
2,3-epoxypropyl-alpha-D-glucopyranoside
-
affinity-labeling reagent, mode of binding, covalently bound to the catalytic residue Glu-172, inactivation mechanism
3,4-epoxybutyl-alpha-D-glucopyranoside
-
affinity-labeling reagent, mode of binding, covalently bound to the catalytic residue Glu-172
4-chloromercuribenzoate
-
inactivation, the enzyme can be reactivated by L-cysteine
5,5'-dithiobis-(2-nitrobenzoic acid)
-
chemical modification of the exposed sulfhydryl groups in beta-amylase from unmalted seeds with 5,5'-dithiobis-(2-nitrobenzoic acid) results in loss of activity. In the beta-amylase from malted seed the 5,5'-dithiobis-(2-nitrobenzoic acid) chemical modification results in the increase in the KM from 2.81 to 4.14 mg/ml
5,5'-dithiobis-2-nitrobenzoate
-
weak
AgNO3
-
1 mM, 94% inhibition
Al2(SO4)3
-
1 mM, 57% inhibition
Al3+
-
mild inhibitor
alpha-cyclodextrin
alpha-cyclohexaamylose
-
-
Aprotinin
-
-
beta-amylase-inhibitor
beta-cyclodextrin
Bi(NO3)3
-
1 mM, 54% inhibition
Ca2+
-
binds at the active site
CO32-
-
-
CuCl2
-
1 mM, 93% inhibition
cyclohexaamylose
D-glucose
D-maltose
D-mannose
125 mM, 6% inhibition, p-nitrophenylmaltopentaoside hydrolysis
diethyl dicarbonate
-
complete inhibition
diethyldicarbonate
-
-
FeCl3
-
1 mM, 16% inhibition
iodoacetamide
iodoacetic acid
Iodosobenzoate
-
-
maltitol
-
behaves as a mixed-type or competitive inhibitor depending on the chain length of the substrate, inhibition mechanism, binds to Site2 in domain B and forms an abortive ESI complex when amylose is used as substrate
maltose
N-bromosuccinimide
N-ethylmaleimide
N-ethylmalimide
-
-
NaCN
-
0.1%
NaNO2
-
partial
O-alpha-D-glucopyranosyl(1-4)O-alpha-D-glucopyranosyl(1-4)D-xylopyranose
-
mode of binding in the active site cleft
O-alpha-D-xylopyranosyl(1-4)O-alpha-D-glucopyranosyl(1-4)O-alpha-D-glucopyranoside
-
mixed-type inhibition, two molecules bind to enzyme
p-chloromercuribenzoate
p-Chloromercuriphenyl sulfonic acid
-
-
p-hydroxymercuribenzoate
-
0.5 mM, 96% inhibition
p-methylsulfonylfluoride
-
3 mM, 100% inhibition
Phenylarsine oxide
-
complete inhibition
Phenylglyoxal
-
3 mM, 27% inhibition
PMSF
-
2 mM
potassium ferricyanide
-
oxidation of the sulfhydryl groups of the enzyme from malted seed in presence of urea results in formation of a dimeric enzyme. The oxidative dimerization leads to inactivation of the enzyme
Schardinger maltodextrins
-
partial
-
Sodium deoxycholate
-
0.001%, 15% inhibition
Sodium dodecyl sulfate
-
0.001%, 57% inhibition
starch
-
at high concentration s
Trypsin inhibitor
-
-
-
Tween 20
-
0.001%, 16% inhibition
Tween 40
-
0.001%, 15% inhibition
ZnSO4
-
1 mM, 54% inhibition
additional information
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
2-mercaptoethanol
-
1 mM, activates
polyethylene glycol 1000
-
1500 Da PEG, increases the enzyme activity by 60% at 0.02% w/v
polyethylene glycol 1500
-
1500 Da PEG, increases the enzyme activity by 77% at 0.02% w/v
-
polyethylene glycol 2000
-
1500 Da PEG, increases the enzyme activity by 58% at 0.02% w/v
polyethylene glycol 400
-
1500 Da PEG, increases the enzyme activity by 7% at 0.02% w/v
-
polyethylene glycol 4600
-
1500 Da PEG, increases the enzyme activity by 74% at 0.02% w/v
polyethylene glycol 600
-
1500 Da PEG, increases the enzyme activity by 19% at 0.02% w/v
polyethylene glycol 8000
-
1500 Da PEG, increases the enzyme activity by 68% at 0.02% w/v
polyvinyl alcohol
-
10 kDa: increases the enzyme activity by 36% at 0.02% w/v, 50 kDa: increases the enzyme activity by 21% at 0.02% w/v
reduced DTT
strong activation of isozyme TR-BAMY
thioredoxin
thioredocins f1, m1, and y1, the isozyme TR-BAMY is positively thioredoxin-regulated
Triton X-100
Triton X-114
-
-
additional information
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.0827
4-nitrophenyl alpha-maltopyranoside
pH 7.0, 90C
0.13 - 0.17
amylodextrin
-
chain lengths geater than 50
-
0.26 - 2.63
amylopectin
0.491 - 0.72
amylose
94.5
maltal
-
-
0.16 - 1.3
maltodextrin
0.9 - 1.83
maltoheptaose
0.89 - 2
maltohexaose
1.02 - 16.2
maltopentaose
4.17 - 18.2
maltotetraose
4.25
maltotriose
pH 5.0, 85C
0.73
p-nitrophenylmaltopentaoside
-
-
0.00317 - 0.77
starch
additional information
additional information
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
962
4-nitrophenyl alpha-maltopyranoside
Pyrococcus furiosus
Q8U2G5
pH 7.0, 90C
0.24 - 2739
amylopectin
2400
amylose
Curculigo pilosa
-
-
0.034 - 1280
maltopentaose
3.95
maltotetraose
Thermococcus sp.
I3ZTN9
pH 5.0, 85C
11.45
maltotriose
Thermococcus sp.
I3ZTN9
pH 5.0, 85C
299 - 6540
starch
additional information
additional information
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.24
maltopentaose
Thermococcus sp.
I3ZTN9
pH 5.0, 85C
272
0.22
maltotetraose
Thermococcus sp.
I3ZTN9
pH 5.0, 85C
269
2.7
maltotriose
Thermococcus sp.
I3ZTN9
pH 5.0, 85C
188
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
13.1 - 13.4
Ca2+
-
pH 4.8, 27C
0.36 - 0.8
cyclohexaamylose
262
D-glucose
pH 5, 20C, iodine staining method
11.7
D-maltose
pH 5, 20C, iodine staining method
2.8 - 5.7
maltitol
18.6
Mg2+
-
pH 4.8, 27C
0.45
O-alpha-D-xylopyranosyl(1-4)O-alpha-D-glucopyranosyl(1-4)O-alpha-D-glucopyranoside
-
pH 7, 25C, wild-type enzyme, amylose as substrate
17.5 - 17.7
Zn2+
-
pH 4.8, 27C
additional information
additional information
-
inhibition kinetics
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.0685
-
pH 5.5, 50C
45.95
Sorghum sp.
-
96 h germination, the enzyme activity increases progressively during seed germination, overview
100
-
-
103.9
-
pH 4.5, 37C, soluble starch
161
Dioscorea batatus
-
-
986
A-7005; type I-B
1187
-
-
4464
-
variant Tainung No.57
4664
-
variant Chailai
additional information
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
3.5 - 7.5
-
-
4 - 5
-
acetate buffer
4.2
mutant Y164Q
4.6
mutant Y164E
5 - 6.5
-
hydrolysis of gelatinized starch
5.4 - 6
-
-
5.5 - 7
-
enzyme from strain 45
5.5
-
degradation of glycogen
5.5 - 6
-
citrate buffer
5.5
-
native enzyme
5.5 - 6.5
-
-
5.5
-
raw corn starch
5.5 - 6
6.7
wild-type enzyme
additional information
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
2 - 8
-
pH 2.0: about 35% of maximal activity, pH 8.0: about 30% of maximal activity
3 - 7
active in the range
3 - 7.5
Dioscorea batatus
-
no activity below pH 3.0 and above pH 7.5
3 - 7.2
-
50% of maximal activity at pH 3.0 and pH 7.2, degradation of glycogen
3 - 9
-
pH 3.0: about 50% of maximal activity, pH 9.0: about 40% of maximal activity
3 - 8
-
pH 3.0: about 70% of maximal activity, pH 8.0: about 60% of maximal activity
3 - 8.5
-
pH 3.0: about 30% of maximal activity, pH 8.5: about 40% of maximal activity
3 - 9
-
pH 3.0: about 70% of maximal activity, pH 9.0: about 15% of maximal activity
4 - 7
Dioscorea batatus
-
pH 4.0: about 25% of maximal activity, pH 7.0: about 50% of maximal activity
4 - 12
-
activity range
4 - 8
-
pH 4.0: about 65% of maximal activity, pH 8.0: about 55% of maximal activity
4 - 6
pH 4.0: about 85% of maximal activity, pH 6.0: about 60% of maximal activity, alpha-1,4-glycosidic linkage hydrolysis of maltotriose
4 - 8
pH 4.0: about 50% of maximal activity, pH 8.0: about 70% of maximal activity, alpha-1,6-glycosidic linkage hydrolysis of 6-O-maltotetraosyl-beta-cyclodextrin
4 - 6.5
-
active in the range
4.5 - 8.5
-
pH 4.5: about 40% of maximal activity, pH 8.5: about 60% of maximal activity
5 - 8
-
pH 5.0: about 55% of maximal activity, pH 8.0: about 60% of maximal activity
5 - 6
-
more than 80% of maximal activity at pH 5.0 and at pH 6.0
5.5 - 10
-
pH 5.5.: about 50% of maximal activity, pH 10.0: about 40% of maximal activity
6 - 9
-
about 75% of maximal activity at pH 6.0 and pH 9.0
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4
-
higher activity of beta-amylase at 4C compared to 10-16 C
20
assay at, starch, amylose or amylopectin as substrate
27
-
assay at
42
-
degradation of glycogen
50 - 55
-
-
65
-
mutant enzyme M185L/S295A/I297V/S350P/S351P/Q352D/A376S
70
-
native immobilized beta-amylase
85
alpha-1,4-glycosidic linkage hydrolysis
98
alpha-1,6-glycosidic linkage hydrolysis
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
20 - 70
-
at different pressure/temperature conditions, up to 700 mPa, overview
20 - 60
-
active in the range
28 - 61
-
28C: about 40% of maximal activity, 61C: about 30% of maximal activity
29 - 41
-
75% of maximal activity at 29C and at 41C
30 - 60
-
30C: about 25% of maximal activity, 60C: about 20% of maximal activity, hyrolysis of raw corn starch
40 - 60
Dioscorea batatus
-
40C: about 30% of maximal activity, 60C: about 50% of maximal activity
50 - 70
50 - 80
-
50C: about 55% of maximal activity, 80C: about 65% of maximal activity
50 - 85
-
50C: about 45% of maximal activity, 85C: about 25% of maximal activity
60 - 95
60C; about 50% of maximal activity, 60C: about 60% of maximal activity, alpha-1,4-glycosidic linkage hydrolysis of maltotriose
80 - 98
activity at 80C is about 50% compared to the activity at 98C, alpha-1,6-glycosidic linkage hydrolysis of 6-O-maltotetraosyl-beta-cyclodextrin
85 - 90
-
85C: 83% of maximal activity, 90C: 32.8% of maximal activity
additional information
freezing tolerance of recombinant plants, overview
pI VALUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4.45 - 6.5
-
detailed isoelectric focusing analysis of pI of different isozymes from 17 Hordeum species, some with several suspecies, four pattern groups, overview
4.5
-
chromatofocusing
4.6 - 4.7
-
isoelectric focusing
4.8 - 6
-
isoelectric focusing analysis of isozyme pI of different cultivars, overview
5.7
-
isoenzyme 50KCBA1, isoelectric focusing
5.9
-
isoenzyme 50KCBA2, isoelectric focusing
6
-
isoenzyme 50KCBA3, isoelectric focusing
6.2
-
isoenzyme 50KCBA4, isoelectric focusing
6.4
-
isoenzyme 50KCBA5, isoelectric focusing