Lactase

Lactase
E. coli lactase tetramer. PDB: 1JYN​
Identifiers
EC no.	3.2.1.108
CAS no.	9031-11-2
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Lactase (EC 3.2.1.108) is an enzyme produced by many organisms and is essential to the complete digestion of whole milk. It breaks down the sugar lactose into its component parts, galactose and glucose. Lactase is found in the brush border of the small intestine of humans and other mammals. People deficient in lactase or lacking functional lactase may experience the symptoms of lactose intolerance after consuming milk products.^[1] Microbial β-galactosidase (often loosely referred to as lactase) can be purchased as a food supplement and is added to milk to produce "lactose-free" milk products.