Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 3.2.1.23 extracted from

  • Kim, Y.-S.; Park, C.-S.; Oh, D.-K.
    Lactulose production from lactose and fructose by a thermostable beta-galactosidase from Sulfolobus solfataricus (2006), Enzyme Microb. Technol., 39, 903-908.
No PubMed abstract available

Application

Application Comment Organism
synthesis the enzyme catalyzes the production of the synthetic disaccharide lactulose (4-O-beta-D-galactopyranosyl-D-fructose) via a transgalactosylation using lactose as a galactose donor and fructose as an acceptor. Lactulose is used in treatment of hyperammonemia and as a gentle laxative. It is also applied to commercial infant formulas and various milk products because it specifically promotes the intestinal proliferation of Bifidobacterium, which creates an acid medium that inhibits the growth of undesirable bacteria Saccharolobus solfataricus

Cloned(Commentary)

Cloned (Comment) Organism
expression in Escherichia coli as a soluble protein that contained a hexa-histidine tag at the carboxyl terminus Saccharolobus solfataricus

Inhibitors

Inhibitors Comment Organism Structure
Ba2+
-
Saccharolobus solfataricus

Metals/Ions

Metals/Ions Comment Organism Structure
Fe2+ increases activity Saccharolobus solfataricus

Molecular Weight [Da]

Molecular Weight [Da] Molecular Weight Maximum [Da] Comment Organism
56561
-
x * 56561, calculated from sequence Saccharolobus solfataricus

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
lactose + H2O Saccharolobus solfataricus
-
D-glucose + D-galactose
-
?
lactose + H2O Saccharolobus solfataricus DSM 1617
-
D-glucose + D-galactose
-
?

Organism

Organism UniProt Comment Textmining
Saccharolobus solfataricus P22498
-
-
Saccharolobus solfataricus DSM 1617 P22498
-
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
lactose + H2O
-
Saccharolobus solfataricus D-glucose + D-galactose
-
?
lactose + H2O
-
Saccharolobus solfataricus DSM 1617 D-glucose + D-galactose
-
?
additional information the enzyme catalyzes the production of the synthetic disaccharide lactulose (4-O-beta-D-galactopyranosyl-D-fructose) via a transgalactosylation using lactose as a galactose donor and fructose as an acceptor Saccharolobus solfataricus ?
-
?
additional information the enzyme catalyzes the production of the synthetic disaccharide lactulose (4-O-beta-D-galactopyranosyl-D-fructose) via a transgalactosylation using lactose as a galactose donor and fructose as an acceptor Saccharolobus solfataricus DSM 1617 ?
-
?

Subunits

Subunits Comment Organism
? x * 56561, calculated from sequence Saccharolobus solfataricus

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
80
-
assay at Saccharolobus solfataricus

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
75
-
half-life: 91 h Saccharolobus solfataricus
80
-
half-life: 48 h Saccharolobus solfataricus
85
-
half-life: 35 h Saccharolobus solfataricus
90
-
half-life: 2.6 h Saccharolobus solfataricus
95
-
half-life: 0.72 h Saccharolobus solfataricus

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
6
-
-
Saccharolobus solfataricus

pH Range

pH Minimum pH Maximum Comment Organism
4 8 pH 4.0: about 45% of maximal activity, pH 8.0: about 80% of maximal activity Saccharolobus solfataricus