EC Number | General Stability | Organism |
---|---|---|
3.2.1.62 | sensitive to repeated freezing and thawing | Homo sapiens |
3.2.1.108 | repeated freezing and thawing, activity declines fast | Homo sapiens |
EC Number | Inhibitors | Comment | Organism | Structure |
---|---|---|---|---|
3.2.1.62 | phlorizin | competitive inhibition of lactase activity; Ki: 0.44 mM | Homo sapiens | |
3.2.1.62 | Tris(hydroxymethyl)aminomethane | competitive inhibition of lactase acitiviy, phlorizin activity not affected, Ki: 12 mM | Homo sapiens | |
3.2.1.108 | phlorizin | - |
Homo sapiens | |
3.2.1.108 | Tris | competitive | Homo sapiens |
EC Number | KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|---|
3.2.1.62 | 0.44 | - |
phlorizin | - |
Homo sapiens | |
3.2.1.62 | 4.4 | - |
4-O-beta-D-glucopyranosyl-D-glucospyranoside | - |
Homo sapiens | |
3.2.1.62 | 21 | - |
4-O-beta-D-galactopyranosyl-D-glucopyranoside | - |
Homo sapiens | |
3.2.1.108 | 0.44 | - |
phlorizin | - |
Homo sapiens | |
3.2.1.108 | 4.4 | - |
cellobiose | - |
Homo sapiens | |
3.2.1.108 | 21 | - |
lactose | - |
Homo sapiens |
EC Number | Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|---|
3.2.1.62 | microvillus | - |
Homo sapiens | 5902 | - |
EC Number | Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|---|
3.2.1.62 | 160000 | - |
2 * 160000, SDS-PAGE | Homo sapiens |
3.2.1.62 | 280000 | - |
gel filtration, hydrophilic form | Homo sapiens |
3.2.1.62 | 320000 | - |
gel filtration, amphiphilic form | Homo sapiens |
3.2.1.108 | 160000 | - |
2 * 160000, SDS-PAGE | Homo sapiens |
3.2.1.108 | 280000 | - |
hydrophilic enzyme form, gel filtration | Homo sapiens |
3.2.1.108 | 320000 | - |
amphiphilic enzyme form, gel filtration | Homo sapiens |
EC Number | Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
3.2.1.62 | 4-O-beta-D-galactopyranosyl-D-glucopyranoside + H2O | Homo sapiens | best substrate | D-galactose + beta-D-glucose | - |
? | |
3.2.1.62 | 4-O-beta-D-glucopyranosyl-D-glucose + H2O | Homo sapiens | cellobiose | beta-D-glucose + D-glucose | - |
? | |
3.2.1.62 | 6-O-beta-D-glucopyranosyl-D-glucose + H2O | Homo sapiens | gentiobiose | beta-D-glucose + D-glucose | - |
? | |
3.2.1.62 | phlorizin + H2O | Homo sapiens | - |
phloretin + beta-D-glucose | - |
? |
EC Number | Organism | UniProt | Comment | Textmining |
---|---|---|---|---|
3.2.1.62 | Homo sapiens | - |
- |
- |
3.2.1.108 | Homo sapiens | - |
- |
- |
EC Number | Purification (Comment) | Organism |
---|---|---|
3.2.1.62 | to homogeneity, immunoadsorbent chromatography | Homo sapiens |
EC Number | Source Tissue | Comment | Organism | Textmining |
---|---|---|---|---|
3.2.1.62 | intestine | small intestine | Homo sapiens | - |
3.2.1.108 | small intestine | - |
Homo sapiens | - |
EC Number | Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|---|
3.2.1.62 | 32 | - |
- |
Homo sapiens |
3.2.1.108 | 32 | - |
- |
Homo sapiens |
EC Number | Storage Stability | Organism |
---|---|---|
3.2.1.62 | -20°C, several months | Homo sapiens |
3.2.1.108 | -20°C, stable for several months | Homo sapiens |
3.2.1.108 | 4°C, stable for several weeks | Homo sapiens |
EC Number | Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
3.2.1.62 | 2-nitrophenyl beta-D-galactopyranoside + H2O | - |
Homo sapiens | 2-nitrophenol + beta-D-galactose | - |
? | |
3.2.1.62 | 4-nitrophenyl beta-D-galactopyranoside + H2O | low activity | Homo sapiens | 4-nitrophenol + beta-D-galactose | - |
? | |
3.2.1.62 | 4-nitrophenyl beta-D-glucopyranoside + H2O | - |
Homo sapiens | 4-nitrophenol + beta-D-glucose | - |
? | |
3.2.1.62 | 4-O-beta-D-galactopyranosyl-D-glucopyranoside + H2O | best substrate | Homo sapiens | D-galactose + beta-D-glucose | - |
? | |
3.2.1.62 | 4-O-beta-D-glucopyranosyl-D-glucose + H2O | cellobiose | Homo sapiens | beta-D-glucose + D-glucose | - |
? | |
3.2.1.62 | 6-O-beta-D-glucopyranosyl-D-glucose + H2O | gentiobiose | Homo sapiens | beta-D-glucose + D-glucose | - |
? | |
3.2.1.62 | phlorizin + H2O | - |
Homo sapiens | phloretin + beta-D-glucose | - |
? | |
3.2.1.108 | cellobiose + H2O | 14% of the activity with lactose | Homo sapiens | 2 beta-D-glucose | - |
? | |
3.2.1.108 | cellulose + H2O | - |
Homo sapiens | beta-D-glucose | - |
? | |
3.2.1.108 | gentiobiose + H2O | 0.7% of the activity with lactose | Homo sapiens | 2 beta-D-glucose | - |
? | |
3.2.1.108 | lactose + H2O | - |
Homo sapiens | D-glucose + D-galactose | - |
? | |
3.2.1.108 | o-nitrophenyl-beta-galactoside + H2O | 17% of the activity with lactose | Homo sapiens | o-nitrophenol + beta-D-galactose | - |
? | |
3.2.1.108 | p-nitrophenyl-beta-galactoside + H2O | 13% of the activity with lactose | Homo sapiens | p-nitrophenol + beta-D-galactose | - |
? | |
3.2.1.108 | p-nitrophenyl-beta-glucoside + H2O | 10% of the activity with lactose | Homo sapiens | p-nitrophenol + beta-D-glucose | - |
? | |
3.2.1.108 | phenyl-beta-galactoside + H2O | 0.1% of the activity with lactose | Homo sapiens | phenol + beta-D-galactose | - |
? | |
3.2.1.108 | phlorizin + H2O | 22% of the activity with lactose | Homo sapiens | phloretin + D-glucose | - |
? |
EC Number | Subunits | Comment | Organism |
---|---|---|---|
3.2.1.62 | dimer | 2 * 160000, SDS-PAGE | Homo sapiens |
3.2.1.108 | dimer | 2 * 160000, SDS-PAGE | Homo sapiens |
EC Number | Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|---|
3.2.1.62 | 4 | - |
no detectable loss of activity for several weeks | Homo sapiens |
EC Number | pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|---|
3.2.1.62 | 5.8 | 6 | - |
Homo sapiens |
3.2.1.108 | 5.8 | 6 | hydrolysis of lactose | Homo sapiens |
EC Number | pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|---|
3.2.1.108 | 5 | 7 | pH 5.0: about 70% of maximal activity, pH 7.0: about 65% of maximal activity | Homo sapiens |
EC Number | pH Stability | pH Stability Maximum | Comment | Organism |
---|---|---|---|---|
3.2.1.62 | 4.2 | 9 | little activity outside this range | Homo sapiens |