Information on EC 3.2.1.23 - beta-galactosidase and Organism(s) Homo sapiens

for references in articles please use BRENDA:EC3.2.1.23
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The taxonomic range for the selected organisms is: Homo sapiens

The enzyme appears in selected viruses and cellular organisms

EC NUMBER
COMMENTARY hide
3.2.1.23
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RECOMMENDED NAME
GeneOntology No.
beta-galactosidase
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
hydrolysis of O-glycosyl bond
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PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
lactose degradation II
-
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xyloglucan degradation II (exoglucanase)
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metabolism of disaccharids
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Galactose metabolism
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Other glycan degradation
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Glycosaminoglycan degradation
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Sphingolipid metabolism
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Glycosphingolipid biosynthesis - ganglio series
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Metabolic pathways
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SYSTEMATIC NAME
IUBMB Comments
beta-D-galactoside galactohydrolase
Some enzymes in this group hydrolyse alpha-L-arabinosides; some animal enzymes also hydrolyse beta-D-fucosides and beta-D-glucosides; cf. EC 3.2.1.108 lactase.
CAS REGISTRY NUMBER
COMMENTARY hide
9031-11-2
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ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
4-methylumbelliferyl beta-D-galactoside + H2O
4-methylumbelliferone + beta-D-galactose
show the reaction diagram
-
-
-
-
?
5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside + H2O
5-bromo-4-chloroindol + beta-D-galactopyranose
show the reaction diagram
-
-
-
-
?
5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside + H2O
?
show the reaction diagram
-
-
-
-
?
5-bromo-4-chloro-3-indolyl-beta-D-galactoside + H2O
5-bromo-4-chloroindol + beta-D-galactose
show the reaction diagram
-
-
-
-
?
5-dodecanoylaminofluorescein di-beta-D-galactopyranoside + H2O
?
show the reaction diagram
-
-
-
-
?
a beta-D-galactoside + H2O
D-galactose + an alcohol
show the reaction diagram
-
-
-
-
?
cellobiose + H2O
D-galactose
show the reaction diagram
-
-
-
-
?
lactose + H2O
D-galactose + D-glucose
show the reaction diagram
-
-
-
-
?
lactose + H2O
D-glucose + D-galactose
show the reaction diagram
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-
-
-
?
lactosyl ceramide + H2O
?
show the reaction diagram
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-
-
-
?
o-nitrophenyl beta-D-fucoside + H2O
o-nitrophenol + beta-D-fucose
show the reaction diagram
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-
-
-
?
o-nitrophenyl-beta-D-galactoside + H2O
o-nitrophenol + beta-D-galactose
show the reaction diagram
-
-
-
-
?
p-nitrophenyl-beta-D-galactoside + H2O
p-nitrophenol + beta-D-galactose
show the reaction diagram
-
-
-
-
?
p-nitrophenyl-beta-D-glucoside + H2O
p-nitrophenol + beta-D-glucose
show the reaction diagram
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-
-
-
?
phlorizin + H2O
D-galactose + ?
show the reaction diagram
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-
-
-
?
additional information
?
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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
a beta-D-galactoside + H2O
D-galactose + an alcohol
show the reaction diagram
-
-
-
-
?
lactose + H2O
D-galactose + D-glucose
show the reaction diagram
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-
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?
additional information
?
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KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.59 - 0.65
4-methylumbelliferyl beta-D-galactoside
additional information
additional information
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SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
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in vivo enzyme activity in different fibroblast lines, cells in different growth stages, overview
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4
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leukocyte enzyme of GM1 gangliosidosis heterozygotes
4.2
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enzyme from leukocytes and fibroblasts of normal individuals, and fibroblast enzyme of GM1 gangliosidosis heterozygotes
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5 - 7
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about 75% of maximal activity at pH 5.0 and at pH 7.0
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
37
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assay at
pI VALUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5.6
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thioredoxin-His portion removed cytoplasmic transduction peptide-beta-gal recombinant protein, calculated from amino acid sequence
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
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of GM1 gangliosidosis heterozygotes compared to normal subjects
Manually annotated by BRENDA team
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overexpressing Neu3
Manually annotated by BRENDA team
additional information
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senescence-associated beta-galactosidase activity is strongly associated with senescent cells, since it is not detectable in quiescent cells or terminally differentiated cells
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
PDB
SCOP
CATH
UNIPROT
ORGANISM
Homo sapiens;
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
120800
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thioredoxin-His portion removed cytoplasmic transduction peptide-beta-gal recombinant protein, calculated from amino acid sequence
170000
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x * 170000, SDS-PAGE
380000
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gel filtration
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
?
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x * 170000, SDS-PAGE
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
proteolytic modification
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in normal cells an 84000 Da precursor is processed first to an intermediate form of higher molecular weight and then to a 64000 Da mature enzyme. In one case of GM1-gangliosidosis a precursor of abnormally high molecular weight is observed, no further processing occurs to the 88000 Da enzyme form
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
42
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80 min,75% loss of leukocte enzyme from GM1 gangliosidosis heterozygotes,70% loss of fibroblast enzyme from GM1 gangliosidosis heterozygotes
45
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50 min, about 50% loss of phlorizin hydrolase activity, about 70% loss of lactase activity
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
84000 Da precursor expressed in recombinant baculovirus-infected Spodoptera frugiperda
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Ni2+-NTA agarose resin column chromatography
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partial
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Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
84000 Da precursor expressed in recombinant baculovirus-infected Spodoptera frugiperda
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expressed in Escherichia coli BL21(DE3) cells
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expression in COS cells
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transfection of fibroblast
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EXPRESSION
ORGANISM
UNIPROT
LITERATURE
in human fibroblasts, the overexpression of plasma membrane associated sialidase Neu3 induces an about 2fold increase of beta-galactosidase expression and activity
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ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
D332N
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mutation seriously reduces catalytic activity
R148S
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mutation has no effect on catalytic activity
additional information
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transfection of beta-galactosidase gene to fibroblast cells in culture using liposomes. 24 h after transfection, treated cells show a higher specific enzyme activity than untreated cells. Cells maintained in culture for 7 days show values similar to those of untreated patients with GM1 gangliosidosis
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
analysis
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the enzyme is a reliable marker for the course of replicative cell senescence
diagnostics
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the enzyme is a reliable marker for the course of replicative cell senescence
medicine
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transfection of beta-galactosidase gene to fibroblast cells in culture using liposomes. 24 h after transfection, treated cells show a higher specific enzyme activity than untreated cells. Cells maintained in culture for 7 days show values similar to those of untreated patients with GM1 gangliosidosis
molecular biology
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senescence-associated beta-galactosidase activity is a widely used biomarker for assessing replicative sensescence in mammalian cells. Quantitative assay of senescence-associated beta-galactosidase activity in mammalian cell extracts. The assay is capable of detecting relatively subtle changes in activity and confirms that confluency and contact inhibition of growth can cause a small increase in the expression of this biomarker. The assay for measuring senescence-associated changes in beta-galactosidase is suitable for mechanistic studies of senescence regulation in which graduated changes in biomarker expression may be anticipated