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Literature summary for 3.2.1.23 extracted from
- beta-Galactosidase (1972), The Enzymes, 3rd Ed. (Boyer, P. D. , ed. ), 7, 617-663.
No PubMed abstract available
Crystallization (Commentary)
| Crystallization (Comment) | Organism |
|---|---|
- |
Escherichia coli |
Inhibitors
| Inhibitors | Comment | Organism | Structure |
|---|---|---|---|
| 2,4-dinitrophenyl-2-deoxy-2-chloro-beta-D-galactoside | - |
Escherichia coli |  |
| 2-mercaptoethanol | - |
Escherichia coli | |
| citrate | - |
Escherichia coli | |
| EDTA | - |
Saccharomyces fragilis | |
| EDTA | - |
Streptococcus pneumoniae | |
| ethanolamine | - |
Escherichia coli | |
| ethylenediamine | - |
Escherichia coli | |
| mercaptoethylamine | - |
Escherichia coli | |
| n-Propanol | - |
Escherichia coli | |
KM Value [mM]
| KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
|---|---|---|---|---|---|
| 0.02 | - |
2-phenylethyl-beta-D-galactoside | - |
Escherichia coli | |
| 0.03 | - |
p-nitrophenyl-beta-D-galactoside | - |
Escherichia coli | |
| 0.12 | - |
2,4-dinitrophenyl-beta-D-galactoside | - |
Escherichia coli | |
| 0.69 | - |
butyl O-beta-D-galactoside | - |
Escherichia coli | |
| 2.83 | - |
beta-D-galactosyl azide | - |
Escherichia coli | |
| 5.5 | - |
lactose | - |
Escherichia coli | |
| 6.9 | - |
methyl O-beta-galactoside | - |
Escherichia coli | |
| 8.3 | - |
allolactose | - |
Escherichia coli | |
Localization
| Localization | Comment | Organism | GeneOntology No. | Textmining |
|---|---|---|---|---|
| lysosome | - |
Rattus norvegicus | 5764 | - |
| lysosome | - |
Bos taurus | 5764 | - |
Metals/Ions
| Metals/Ions | Comment | Organism | Structure |
|---|---|---|---|
| Ca2+ | - |
Rattus norvegicus | |
| Ca2+ | - |
Kluyveromyces lactis | |
| Ca2+ | 0.01 mM, activation at low concentrations in a system containing Na+ at optimal concentration | Escherichia coli | |
| Co2+ | - |
Saccharomyces fragilis | |
| Co2+ | 0.1 mM, activation in a system containing Na+ at optimal concentration | Escherichia coli | |
| Fe2+ | 0.01-0.1 mM, activation in a system containing Na+ at optimal concentration | Escherichia coli | |
| K+ | - |
Saccharomyces fragilis | |
| K+ | - |
Kluyveromyces lactis | |
| K+ | activates hydrolysis of p-nitrophenyl-beta-D-galactoside and p-nitrophenyl alpha-L-arabinoside more effectively than Na+ | Escherichia coli | |
| K+ | activates hydrolysis of lactose more effectively than Na+ | Escherichia coli | |
| Mg2+ | - |
Saccharomyces fragilis | |
| Mg2+ | - |
Kluyveromyces lactis | |
| Mg2+ | 0.1-10 mM, activation in a system containing Na+ at optimal concentration | Escherichia coli | |
| Mn2+ | - |
Rattus norvegicus | |
| Mn2+ | - |
Saccharomyces fragilis | |
| Mn2+ | 0.01-0.1 mM, activation in a system containing Na+ at optimal concentration | Escherichia coli | |
| Na+ | - |
Rattus norvegicus | |
| Na+ | - |
Kluyveromyces lactis | |
| Na+ | activates hydrolysis of o-nitrophenyl-beta-D-galactoside more effectively than K+ | Escherichia coli | |
| Ni2+ | 0.1 mM, activation in a system containing Na+ at optimal concentration | Escherichia coli | |
| Zn2+ | 0.01-0.1 mM, activation in a system containing Na+ at optimal concentration | Escherichia coli | |
Molecular Weight [Da]
| Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
|---|---|---|---|
| 118000 | - |
4 * 118000, equilibrium sedimentation in 8 M urea | Escherichia coli |
| 135000 | - |
4 * 135000, low speed sedimentation without reaching equilibrium in urea hydrochloride | Streptococcus pneumoniae |
| 516000 | - |
strain ML 309, calculation from sedimentation and diffusion data | Escherichia coli |
| 521000 | - |
strain ML 35, calculation from sedimentation and diffusion data | Escherichia coli |
Organism
| Organism | UniProt | Comment | Textmining |
|---|---|---|---|
| Aeromonas caviae | - |
- |
- |
| Bacillus subtilis | - |
- |
- |
| Bos taurus | - |
- |
- |
| Enterobacter cloacae | - |
- |
- |
| Escherichia coli | - |
- |
- |
| Escherichia coli ML 309 | - |
- |
- |
| Escherichia coli ML 35 | - |
- |
- |
| Hamamotoa singularis | - |
- |
- |
| Helix pomatia | - |
- |
- |
| Homo sapiens | - |
- |
- |
| Kluyveromyces lactis | - |
- |
- |
| Lactococcus lactis | - |
- |
- |
| Ovis aries | - |
- |
- |
| Paracolobactrum aerogenoides | - |
- |
- |
| Priestia megaterium | - |
- |
- |
| Rattus norvegicus | - |
- |
- |
| Saccharomyces fragilis | - |
- |
- |
| Shigella dysenteriae | - |
- |
- |
| Streptococcus pneumoniae | - |
- |
- |
| Tritrichomonas suis | - |
- |
- |
Posttranslational Modification
| Posttranslational Modification | Comment | Organism |
|---|---|---|
| glycoprotein | - |
Rattus norvegicus |
| glycoprotein | enzyme from calf intestine contains 88% carbohydrate | Bos taurus |
| no modification | enzyme contains no carbohydrate or phosphate | Escherichia coli |
Purification (Commentary)
| Purification (Comment) | Organism |
|---|---|
- |
Bos taurus |
| partial | Homo sapiens |
Reaction
| Reaction | Comment | Organism | Reaction ID |
|---|---|---|---|
| beta-D-galactopyranosyl-(1-4)-beta-D-galactopyranosyl-(1-6)-beta-D-galactopyranosyl-(1-3)-beta-D-galactopyranose + 3 H2O = 4 beta-D-galactopyranose | mechanism | Escherichia coli |
Source Tissue
| Source Tissue | Comment | Organism | Textmining |
|---|---|---|---|
| brain | - |
Rattus norvegicus | - |
| brain | - |
Bos taurus | - |
| intestine | - |
Homo sapiens | - |
| intestine | - |
Bos taurus | - |
Specific Activity [micromol/min/mg]
| Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
|---|---|---|---|
| additional information | - |
- |
Rattus norvegicus |
| additional information | - |
- |
Bos taurus |
| additional information | - |
assay methods | Escherichia coli |
Substrates and Products (Substrate)
| Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| 2,4-dinitrophenyl-beta-D-galactoside + H2O | - |
Escherichia coli | 2,4-dinitrophenol + beta-D-galactose | - |
? | |
| 2,4-dinitrophenyl-beta-D-glucoside + H2O | activity is 10000 times lower than with 2,4-dinitrophenyl-beta-D-galactoside | Escherichia coli | 2,4-dinitrophenol + beta-D-glucose | - |
? | |
| 2-phenylethyl-beta-D-galactoside + H2O | - |
Escherichia coli | 2-phenylethanol + beta-D-galactose | - |
? | |
| allolactose + H2O | - |
Escherichia coli | D-galactose + D-glucose | - |
? | |
| beta-D-galactosyl azide + H2O | - |
Escherichia coli | azide + beta-D-galactose | - |
? | |
| beta-D-galactosyl fluoride + H2O | - |
Escherichia coli | fluoride + beta-D-galactose | - |
? | |
| butyl O-beta-D-galactoside + H2O | - |
Escherichia coli | butanol + beta-D-galactose | - |
? | |
| butyl O-beta-galactoside + H2O | - |
Escherichia coli | butanol + beta-D-galactose | - |
? | |
| ethyl-beta-D-galactoside + H2O | - |
Escherichia coli | ethanol + beta-D-galactose | - |
? | |
| lactose + H2O | - |
Escherichia coli | D-glucose + D-galactose | - |
? | |
| lactose + H2O | - |
Homo sapiens | D-glucose + D-galactose | - |
? | |
| lactose + H2O | - |
Rattus norvegicus | D-glucose + D-galactose | - |
? | |
| lactose + H2O | - |
Escherichia coli ML 309 | D-glucose + D-galactose | - |
? | |
| lactose + H2O | - |
Escherichia coli ML 35 | D-glucose + D-galactose | - |
? | |
| methyl O-beta-galactoside + H2O | - |
Escherichia coli | methanol + beta-D-galactose | - |
? | |
| additional information | transgalactosylation with o-nitrophenyl-beta-D-galactoside or phenyl-beta-D-galactoside as galactosyl donor and methanol, glycerol, 2-mercaptoethanol, Tris or 2-phenylethyl alcohol as acceptor | Escherichia coli | ? | - |
? | |
| additional information | synthesis of beta-D-galactosides by the direct condensation of free galactose and alcohols | Escherichia coli | ? | - |
? | |
| additional information | transgalactosylation with o-nitrophenyl-beta-D-galactoside or phenyl-beta-D-galactoside as galactosyl donor and methanol, glycerol, 2-mercaptoethanol, Tris or 2-phenylethyl alcohol as acceptor | Escherichia coli ML 309 | ? | - |
? | |
| additional information | synthesis of beta-D-galactosides by the direct condensation of free galactose and alcohols | Escherichia coli ML 309 | ? | - |
? | |
| additional information | transgalactosylation with o-nitrophenyl-beta-D-galactoside or phenyl-beta-D-galactoside as galactosyl donor and methanol, glycerol, 2-mercaptoethanol, Tris or 2-phenylethyl alcohol as acceptor | Escherichia coli ML 35 | ? | - |
? | |
| additional information | synthesis of beta-D-galactosides by the direct condensation of free galactose and alcohols | Escherichia coli ML 35 | ? | - |
? | |
| p-nitrophenyl alpha-L-arabinoside + H2O | - |
Escherichia coli | p-nitrophenol + alpha-L-arabinose | - |
? | |
| p-nitrophenyl alpha-L-arabinoside + H2O | - |
Bos taurus | p-nitrophenol + alpha-L-arabinose | - |
? | |
| p-nitrophenyl alpha-L-arabinoside + H2O | - |
Escherichia coli ML 309 | p-nitrophenol + alpha-L-arabinose | - |
? | |
| p-nitrophenyl alpha-L-arabinoside + H2O | - |
Escherichia coli ML 35 | p-nitrophenol + alpha-L-arabinose | - |
? | |
| p-nitrophenyl-beta-D-galactoside + H2O | - |
Escherichia coli | p-nitrophenol + beta-D-galactose | - |
? | |
| p-nitrophenyl-beta-D-galactoside + H2O | - |
Homo sapiens | p-nitrophenol + beta-D-galactose | - |
? | |
| p-nitrophenyl-beta-D-galactoside + H2O | - |
Rattus norvegicus | p-nitrophenol + beta-D-galactose | - |
? | |
| p-nitrophenyl-beta-D-galactoside + H2O | - |
Bos taurus | p-nitrophenol + beta-D-galactose | - |
? | |
| p-nitrophenyl-beta-D-galactoside + H2O | - |
Priestia megaterium | p-nitrophenol + beta-D-galactose | - |
? | |
| p-nitrophenyl-beta-D-galactoside + H2O | - |
Escherichia coli ML 309 | p-nitrophenol + beta-D-galactose | - |
? | |
| p-nitrophenyl-beta-D-galactoside + H2O | - |
Escherichia coli ML 35 | p-nitrophenol + beta-D-galactose | - |
? | |
| phenyl-beta-D-galactoside + H2O | - |
Escherichia coli | phenol + beta-D-galactose | - |
? | |
Subunits
| Subunits | Comment | Organism |
|---|---|---|
| tetramer | 4 * 135000, low speed sedimentation without reaching equilibrium in urea hydrochloride | Streptococcus pneumoniae |
| tetramer | 4 * 118000, equilibrium sedimentation in 8 M urea | Escherichia coli |
Temperature Stability [°C]
| Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
|---|---|---|---|
| additional information | - |
- |
Saccharomyces fragilis |
| additional information | - |
enzyme becomes remarkably heat labile in the presence of fructose 1,6-diphosphate | Escherichia coli |
| 55 | - |
40 min, in presence of 0.1 M mercaptoethanol and 0.01 MgCl2, 50% loss of activity. Without mercaptoethanol complete loss of activity after 10 min | Escherichia coli |
Turnover Number [1/s]
| Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
|---|---|---|---|---|---|
| 26 | - |
beta-D-galactosyl azide | - |
Escherichia coli | |
pH Optimum
| pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
|---|---|---|---|
| 6.8 | - |
- |
Saccharomyces fragilis |
| 6.8 | - |
hydrolysis of o-nitrophenyl-beta-D-galactoside, in presence of 2 mM Mg2+ | Escherichia coli |
| 7.4 | - |
hydrolysis of o-nitrophenyl-beta-D-galactoside, without Mg2+ | Escherichia coli |
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