Lactase Phlorizin Hydrolase

From Anvita Health Wiki

Contents 1 Function 2 Structure 3 Compartment 4 Expression 5 Pathology 6 Pharmacology 7 More General Terms 8 Additional Terms 9 Internet Database 10 References

Function

• LCT splits lactose in the small intestine

* lactose + H2O <-->  D-galactose + D-glucose 
* Glycosyl-N-acylsphingosine + H2O  
*           <-->  
* N-acylsphingosine + a sugar

Structure

• exhibits 4 regions ( I-IV) of internal homology; thus LPH might have evolved by two cycles of partial gene duplication
• belongs to the glycosyl hydrolase 1 family

Compartment

• apical cell membrane
• brush border

Expression

• intestine
• developmental down-regulation of lactase activity during childhood or early adulthood
• down-regulation of lactase activity operates at the transcriptional level & it is associated with a noncoding variation in the MCM6 gene, located in the upstream vicinity of LCT

Pathology

• defects in LCT are the cause of congenital lactase deficiency
• developmental down-regulation of lactase activity during childhood or early adulthood results in lactose intolerance

Pharmacology

• oral formulation used in treatment of lactase deficiency

More General Terms

• glucosidase
• membrane protein
• metabolic agent (metabolic modifier)

Additional Terms

• lactase

Internet Database

UniProt: [1]
Entrez gene: 3938
Kegg: [2]
OMIM: 223000
OMIM: 223100
OMIM: 603202
Prosite: [3]
Prosite: [4]

References

1. UniProt [5]
2. GeneReviews [6]
3. Wikipedia; Note: lactase entry [7]

lactase phlorizin hydrolase; lactase glycosylceramidase; lactase (LCT, LPH)