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Domain

The glycosyl hydrolase-1 3/region III carries the phlorizin hydrolase/glycosylceramidase activities.

The glycosyl hydrolase-1 4/region IV carries the lactase activity.

Function

Broad specificity glycosidase of the intestinal brush border membrane that hydrolyzes lactose, the main sugar in mammalian milk, to produce D-glucose and D-galactose (PubMed:12594539, PubMed:16400612, PubMed:3929764, PubMed:9762914). The mature protein is composed of two domains that catalyze the hydrolysis of beta-glucopyranosides and beta-galactopyranosides, with a preference for hydrophilic aglycones (in lactose and cellobiose) for one domain and hydrophobic aglycones (in phlorizin and glycosylceramides) for the other (PubMed:12594539, PubMed:3929764, PubMed:9762914).

Involvement in disease

Congenital lactase deficiency

COLACD

Autosomal recessive, rare and severe gastrointestinal disorder. It is characterized by watery diarrhea in infants fed with breast milk or other lactose-containing formulas. An almost total lack of LCT activity is found in jejunal biopsy material of patients with congenital lactase deficiency. Opposite to congenital lactase deficiency, also known as lactose intolerance, is the most common enzyme deficiency worldwide. It is caused by developmental down-regulation of lactase activity during childhood or early adulthood. The decline of lactase activity is a normal physiological phenomenon; however, the majority of Northern Europeans have the ability to maintain lactase activity and digest lactose throughout life (lactase persistence). The down-regulation of lactase activity operates at the transcriptional level and it is associated with a noncoding variation in the MCM6 gene, located in the upstream vicinity of LCT.

None

The disease is caused by variants affecting the gene represented in this entry.

Post-translational modifications

N-glycosylated.

Sequence similarities

Belongs to the glycosyl hydrolase 1 family.

Tissue specificity

Specifically expressed in small intestine.

Cellular localization

  • Apical cell membrane
  • Single-pass type I membrane protein
  • Brush border.

Alternative names

LPH, LCT, Lactase/phlorizin hydrolase, Lactase/glycosylceramidase

Target type

Proteins

Primary research area

Developmental Biology

Molecular weight

218587Da

We found 1 product in 1 category

Primary Antibodies

Target

Application

Reactive species

Search our catalogue for 'LCT' (1)

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