Hipolaktazja typu dorosłych - od genu do białka

Lactase (lactase phlorizin hydroxylase - LPH) is an enzyme belonging to the β-galactosidase family. Its activity is essential for digestion of lactose, a milk originated sugar. Lactase gene (LPH, MIM: 603202) is located on the long arm of the second chromosome. The regulation of LPH expression occurs at three levels: cellular, organic and developmental. The enzyme is synthesized in the brush border of the small intestine as a precursor protein pre-pro LPH, constructed from 5 domains. As a result of posttranslational processing the final product, lactase is created. Activity and structure of lactase is influenced by several factors. With the weaning time, lactase activity in the majority of the world's population is significantly reduced. The maintenance of high lactase activity throughout the entire life span has become possible thanks to the emergence, in the course of the evolution, of -13910C> T lactase gene polymorphism. The actual evidence related to functioning and regulation of LPH and its protein product in the context of adult-type hypolactasia has been presented.