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Information on EC 3.2.1.108 - lactase and Organism(s) Homo sapiens and UniProt Accession P09848

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     3 Hydrolases
         3.2 Glycosylases
             3.2.1 Glycosidases, i.e. enzymes that hydrolyse O- and S-glycosyl compounds
                3.2.1.108 lactase
IUBMB Comments
The enzyme from intestinal mucosa is isolated as a complex that also catalyses the reaction of EC 3.2.1.62 glycosylceramidase. cf. EC 3.2.1.33 amylo-alpha-1,6-glucosidase.
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Select one or more organisms in this record:
This record set is specific for:
Homo sapiens
UNIPROT: P09848
Word Map
The expected taxonomic range for this enzyme is: Eukaryota, Bacteria
The taxonomic range for the selected organisms is: Homo sapiens
Reaction Schemes
Synonyms
intestinal lactase, lactase, lactase phlorizin hydrolase, lactase-phlorizin hydrolase, lactase-phlorizin hydrolase LPH, lactase-phlorozin hydrolase, lactase/phlorizin hydrolase, LPH, more
SYNONYM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
lactase
lactase phlorizin hydrolase
247
-
lactase-phlorizin hydrolase
lactase-phlorizin hydrolase LPH
247
-
lactase-phlorozin hydrolase
247
-
lactase/phlorizin hydrolase
-
-
-
-
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
hydrolysis
-
-
hydrolysis of O-glycosyl bond
PATHWAY SOURCE
PATHWAYS
SYSTEMATIC NAME
IUBMB Comments
lactose galactohydrolase
The enzyme from intestinal mucosa is isolated as a complex that also catalyses the reaction of EC 3.2.1.62 glycosylceramidase. cf. EC 3.2.1.33 amylo-alpha-1,6-glucosidase.
CAS REGISTRY NUMBER
COMMENTARY hide
9031-11-2
-
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
cellobiose + H2O
2 beta-D-glucose
show the reaction diagram
-
14% of the activity with lactose
-
-
?
cellotetraose + 3 H2O
4 beta-D-glucose
show the reaction diagram
-
9% of the activity with lactose
-
-
?
cellotriose + H2O
beta-D-glucose
show the reaction diagram
-
14% of the activity with lactose
-
-
?
cellulose + H2O
beta-D-glucose
show the reaction diagram
gentiobiose + H2O
2 beta-D-glucose
show the reaction diagram
-
0.7% of the activity with lactose
-
-
?
lactose + H2O
D-galactose + D-glucose
show the reaction diagram
lactose + H2O
D-glucose + D-galactose
show the reaction diagram
o-nitrophenyl-beta-galactoside + H2O
o-nitrophenol + beta-D-galactose
show the reaction diagram
-
17% of the activity with lactose
-
-
?
p-nitrophenyl-beta-galactoside + H2O
p-nitrophenol + beta-D-galactose
show the reaction diagram
-
13% of the activity with lactose
-
-
?
p-nitrophenyl-beta-glucoside + H2O
p-nitrophenol + beta-D-glucose
show the reaction diagram
-
10% of the activity with lactose
-
-
?
phenyl-beta-galactoside + H2O
phenol + beta-D-galactose
show the reaction diagram
-
0.1% of the activity with lactose
-
-
?
phlorizin
phloretin + D-glucose
show the reaction diagram
-
37°C, 2h
-
-
?
phlorizin + H2O
phloretin + D-glucose
show the reaction diagram
NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
lactose + H2O
D-galactose + D-glucose
show the reaction diagram
lactose + H2O
D-glucose + D-galactose
show the reaction diagram
-
rotavirus RRV infection affects the lactose metabolism of enterocytes in the intestine, overview
-
-
?
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
NSP4
-
impairment of lactase activity observed during rotavirus infection results from an inhibitory action of the secreted non-structural rotavirus protein NSP4
-
phlorizin
-
-
Tris
-
competitive
additional information
-
rotavirus impairs lactase enzymatic activity by an NSP4-dependant mechanism in brush border of human enterocyte-like Caco-2 cells, the infected brush border membranes show an enzyme with altered kinetics, overview
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
-
determination of disaccharidase activities in intestinal biopsy samples show a highly significant correlation between lactase activity and the T/G-13915 genotype
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
4.4
cellobiose
-
-
21 - 30
lactose
0.44
phlorizin
-
-
additional information
additional information
-
rotavirus infection decreases Vmax of LPH, overview
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.00164
-
non-infected cells, lactase enzyme activity in cell homogenates
0.00167
-
rhesus monkey rotavirus-, RRV, infected cells, lactase enzyme activity in cell homogenates
0.002
-
mutant S218fsX224, mean lactase activity
0.0021
-
mutant Y1390X, mean lactase activity
0.00219
-
rhesus monkey rotavirus-, RRV, infected cells, lactase enzyme activity in brush border-enriched fraction
0.003
-
mutant G1363S, mean lactase activity
0.00344
-
non-infected cells, lactase enzyme activity in brush border-enriched fraction
0.00359
-
UV, psoralen-inactivated RRV infected cells, lactase enzyme activity in brush border-enriched fraction
0.005
-
mutant Q268H, mean lactase activity; mutant S1666fsX1722, mean lactase activity
additional information
-
20% enzyme activity of mutant G1363S after incubation at 20°C for 22h; enzymatic activity of mutant G1363S below detection line
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5.8 - 6
-
hydrolysis of lactose
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5 - 7
-
pH 5.0: about 70% of maximal activity, pH 7.0: about 65% of maximal activity
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
20
-
restoring of enzymatic activity of misfolded mutation G1363S by expression at 20°C
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
-
UniProt
Manually annotated by BRENDA team
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
-
; fully differentiated, intestinal enterocyte-like cells
Manually annotated by BRENDA team
-
predominantly at the apical membrane
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
-
misfolded mutation G1363S
Manually annotated by BRENDA team
UNIPROT
ENTRY NAME
ORGANISM
NO. OF AA
NO. OF TRANSM. HELICES
MOLECULAR WEIGHT[Da]
SOURCE
Sequence
LPH_HUMAN
1927
1
218587
Swiss-Prot
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
130000
-
molecular mass after N-glycosidase F treatment of LPH; N-glycosylated LPH, gel filtration
140000
-
x * 140000, SDS-PAGE
160000
220000
-
apparent molecular mass of the high-mannose LPH form, determinated by pulse-chase experiments
280000
-
hydrophilic enzyme form, gel filtration
320000
SUBUNIT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
?
-
x * 140000, SDS-PAGE
dimer
-
2 * 160000, SDS-PAGE
homodimer
-
2* 145000
additional information
-
region LAC236 between R1647 and T1882 is implicated in the dimerization process of pro-enzyme
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
glycoprotein
proteolytic modification
PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
E1612X
results in congenital lactase deficiency
G1363S
results in congenital lactase deficiency
R1587H
results in congenital lactase deficiency
S688P
results in congenital lactase deficiency
Y1390X
results in congenital lactase deficiency
D1711N
-
introduction of potential N-glycosilation site, no enzymic activity, probably due to altered protein folding pattern and reduced dimerization efficiency
G1363S
I1697N
-
introduction of potential N-glycosilation site, no enzymic activity, probably due to altered protein folding pattern and reduced dimerization efficiency
more |
-
CC13910, lactose intolerance, low lactase genotype, no predispose for cataracts with mutation of galactose-1-phosphate uridyl transferase
P1743S
-
introduction of potential N-glycosilation site, no enzymic activity, probably due to altered protein folding pattern and reduced dimerization efficiency
Q268H
-
congential lactase deficiency, CLD, mutation, DNA mutation c.804G->C, genotype compound heterozygote for Y1390X
S1666fsX1722
-
congential lactase deficiency, CLD, mutation, DNA mutation c.4998_5001delTGAG, genotype compound heterozygote for Y1390X
S218fsX224
-
congential lactase deficiency, CLD, mutation, DNA mutation c.653_654delCT, genotype compound heterozygote for Y1390X
Y1390X
-
congential lactase deficiency, CLD, mutation, DNA mutation c.4170T->A, genotype homozygote
additional information
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
repeated freezing and thawing, activity declines fast
-
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
-20°C, stable for several months
-
4°C, stable for several weeks
-
CLONED/commentary
ORGANISM
UNIPROT
LITERATURE
expression in Cos-1 cells
-
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
medicine
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Jacob, R.; Weiner, J.R.; Stadge, S.; Naim, H.Y.
Additional N-glycosylation and its impact on the folding of intestinal lactase-phlorizin hydrolase
J. Biol. Chem.
275
10630-10637
2000
Homo sapiens
Manually annotated by BRENDA team
Skovbjerg, H.; Sjöström, H.; Noren, O.
Purification and characterization of amphiphilic lactase/phlorizin hydrolase from human small intestine
Eur. J. Biochem.
114
653-661
1981
Homo sapiens
Manually annotated by BRENDA team
Skovbjerg, H.; Noren, O.; Sjöström, H.; Danielsen, E.M.; Enevoldsen, B.S.
Further characterization of intestinal lactase/phlorizin hydrolase
Biochim. Biophys. Acta
707
89-97
1982
Homo sapiens, Sus scrofa
Manually annotated by BRENDA team
Schlegel-Haueter, S.; Hore, P.; Kerry, K.R.; Semenza, G.
The preparation of lactase and glucoamylase of rat small intestine
Biochim. Biophys. Acta
258
506-519
1972
Homo sapiens, Rattus norvegicus
Manually annotated by BRENDA team
Jacob, R.; Peters, K.; Naim, H.Y.
Prosequence of human lactase-phlorizin hydrolase modulates the folding of mature enzyme
J. Biol. Chem.
277
8217-8225
2002
Homo sapiens
Manually annotated by BRENDA team
Lewinsky, R.H.; Jensen, T.G.; M?ller, J.; Stensballe, A.; Olsen, J.; Troelsen, J.T.
T-13910 DNA variant associated with lactase persistence interacts with Oct-1 and stimulates lactase promoter activity in vitro
Hum. Mol. Genet.
14
3945-3953
2005
Homo sapiens
Manually annotated by BRENDA team
Beau, I.; Cotte-Laffitte, J.; Geniteau-Legendre, M.; Estes, M.K.; Servin, A.L.
An NSP4-dependant mechanism by which rotavirus impairs lactase enzymatic activity in brush border of human enterocyte-like Caco-2 cells
Cell. Microbiol.
9
2254-2266
2007
Homo sapiens
Manually annotated by BRENDA team
Kuokkanen, M.; Kokkonen, J.; Enattah, N.S.; Ylisaukko-Oja, T.; Komu, H.; Varilo, T.; Peltonen, L.; Savilahti, E.; Jarvela, I.
Mutations in the translated region of the lactase gene (LCT) underlie congenital lactase deficiency
Am. J. Hum. Genet.
78
339-344
2006
Homo sapiens
Manually annotated by BRENDA team
Bernardes-Silva Carlos Felip, B.C.; Pereira Alexandre , P.A.; de Fatima Alves da Mota Glori, d.F.; Krieger Jose Eduard, K.J.; Laudanna Antonio Atili, L.A.
Lactase persistence/non-persistence variants, C/T_13910 and G/A_22018, as a diagnostic tool for lactose intolerance in IBS patients
Clin. Chim. Acta
386
7-11
2007
Homo sapiens
Manually annotated by BRENDA team
Tamura, A.; Shiomi, T.; Hachiya, S.; Shigematsu, N.; Hara, H.
Low activities of intestinal lactase suppress the early phase absorption of soy isoflavones in Japanese adults
Clin. Nutr.
27
248-253
2008
Homo sapiens
Manually annotated by BRENDA team
Imtiaz , I.F.; Savilahti , S.E.; Sarnesto , S.A.; Trabzuni , T.D.; Al-Kahtani , A.K.; Kagevi , K.I.; Rashed M. , R.M.; Meyer B. , M.B.; Jarvela , J.I.
The T/G 13915 variant upstream of the lactase gene (LCT) is the founder allele of lactase persistence in an urban Saudi population
J. Med. Genet.
44
e89-e89
2007
Homo sapiens
Manually annotated by BRENDA team
Torniainen, S.; Freddara, R.; Routi, T.; Gijsbers, C.; Catassi, C.; Hoeglund, P.; Savilahti, E.; Jaervelae, I.
Four novel mutations in the lactase gene (LCT) underlying congenital lactase deficiency (CLD)
BMC Gastroenterol.
9
8
2009
Homo sapiens, Homo sapiens (P09848)
Manually annotated by BRENDA team
Karas-Kuzelicki, N.; Pfeifer, V.; Lukac-Bajalo, J.
Synergistic effect of high lactase activity genotype and galactose-1-phosphate uridyl transferase (GALT) mutations on idiopathic presenile cataract formation
Clin. Biochem.
41
869-874
2008
Homo sapiens
Manually annotated by BRENDA team
Behrendt, M.; Keiser, M.; Hoch, M.; Naim, H.Y.
Impaired trafficking and subcellular localization of a mutant lactase associated with congenital lactase deficiency
Gastroenterology
136
2295-2303
2009
Homo sapiens
Manually annotated by BRENDA team
Khabarova, Y.A.; Torniainen, S.T.; Nurmi, H.A.; Jaervelae, I.E.; Isokoski, M.K.; Mattila, K.J.
Prevalence of lactase persistent/non-persistent genotypes and milk consumption in a young population in north-west Russia
World J. Gastroenterol.
15
1849-1853
2009
Homo sapiens
Manually annotated by BRENDA team
Koek, W.; van Meurs, J.; van der Eerden, B.; Rivadeneira, F.; Zillikens, M.; Hofman, A.; Obermayer-Pietsch, B.; Lips, P.; Pols, H.; Uitterlinden, A.; van Leeuwen, J.
The T-13910C polymorphism in the lactase phlorizin hydrolase gene is associated with differences in serum calcium levels and calcium intake
J. Bone Miner. Res.
25
1980-1987
2010
Homo sapiens
Manually annotated by BRENDA team
Ingram, C.J.; Raga, T.O.; Tarekegn, A.; Browning, S.L.; Elamin, M.F.; Bekele, E.; Thomas, M.G.; Weale, M.E.; Bradman, N.; Swallow, D.M.
Multiple rare variants as a cause of a common phenotype: several different lactase persistence associated alleles in a single ethnic group
J. Mol. Evol.
69
579-588
2009
Homo sapiens
Manually annotated by BRENDA team
Khabarova, Y.; Torniainen, S.; Savilahti, E.; Isokoski, M.; Mattila, K.; Jaervelae, I.
The -13914G>A variant upstream of the lactase gene (LCT) is associated with lactase persistence/non-persistence
Scand. J. Clin. Lab. Invest.
70
354-357
2010
Homo sapiens
Manually annotated by BRENDA team
Kuchay, R.A.; Thapa, B.R.; Mahmood, A.; Mahmood, S.
Effect of C/T -13910 cis-acting regulatory variant on expression and activity of lactase in Indian children and its implication for early genetic screening of adult-type hypolactasia
Clin. Chim. Acta
412
1924-1930
2011
Homo sapiens
Manually annotated by BRENDA team
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