LCT
LCT (lactase, also known as lactase/phlorizin hydrolase) is a broad-specificity glycosidase of the intestinal brush border membrane. It hydrolyses lactose, the main sugar in mammalian milk, into D-glucose and D-galactose. Browse Assay Genie's current range of LCT research reagents below, or read on for the biology behind the target.
LCT is a broad-specificity glycosidase found in the intestinal brush border membrane. Its best-known role is the hydrolysis of lactose, the main sugar in mammalian milk, which yields D-glucose and D-galactose. The mature protein is made up of two domains that catalyse the hydrolysis of beta-glucopyranosides and beta-galactopyranosides. The domains differ in substrate preference. One favours hydrophilic aglycones, as in lactose and cellobiose. The other favours hydrophobic aglycones, as in phlorizin and glycosylceramides. This dual activity explains the alternative name lactase/phlorizin hydrolase.
The LCT gene encodes a preproprotein that is proteolytically processed to generate the mature enzyme. The enzyme is integral to the plasma membrane and is located at the apical cell membrane. It has both phlorizin hydrolase activity and lactase activity. LCT belongs to the glycosyl hydrolase 1 family, which HGNC lists as glycoside hydrolase family 1. Researchers studying the LCT protein often work on brush border digestion and on the processing of membrane-bound glycosidases.
LCT is relevant to human disease and variation. Mutations in the gene are associated with congenital lactase deficiency. Polymorphisms in the gene are associated with lactase persistence, in which intestinal lactase activity stays at childhood levels into adulthood. These links make LCT a reference point for work on carbohydrate digestion, lactose handling and the genetics of enzyme regulation. The rat ortholog is called Lct, which supports comparative work in rodent models.
LCT hydrolyses lactose from milk into D-glucose and D-galactose at the intestinal brush border membrane.
Mutations in LCT are associated with congenital lactase deficiency, making the gene central to studies of this disorder.
Polymorphisms in LCT are associated with lactase persistence, where intestinal lactase activity remains at childhood levels in adulthood.
Its two domains act on distinct substrates, including lactose, cellobiose, phlorizin and glycosylceramides, which makes LCT a model for domain-specific hydrolysis.
LCT is a glycosidase of the intestinal brush border membrane. It hydrolyses lactose, the main sugar in mammalian milk, into D-glucose and D-galactose. Its two domains also act on other beta-glycosides, such as cellobiose, phlorizin and glycosylceramides, with different preferences for hydrophilic or hydrophobic aglycones.
The name reflects two activities in one protein. The enzyme has lactase activity and phlorizin hydrolase activity, carried out by its two domains. HGNC names the gene lactase, while UniProt uses lactase/phlorizin hydrolase. The enzyme is made as a preproprotein that is processed into the mature form.
Yes. Mutations in LCT are associated with congenital lactase deficiency. Polymorphisms in the gene are associated with lactase persistence, where intestinal lactase activity stays at childhood levels into adulthood. A rat ortholog, Lct, is known; check the datasheet of any product for its validated reactivity.
Other glycoside hydrolases and brush border digestive enzymes with research reagents at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P09848; product specifications from Assay Genie datasheets.