- Enteropeptidase
protein
Name=protease, serine, 7 (enteropeptidase)
caption=Crystal structure of Enteropeptidase with aninhibitor
width=
HGNCid=9490
Symbol=PRSS7
AltSymbols=
EntrezGene=5651
OMIM=606635
RefSeq=NM_002772
UniProt=P98073
PDB=
ECnumber=
Chromosome=21
Arm=q
Band=21
LocusSupplementaryData=Enteropeptidase (also called enterokinase) is an
enzyme involved in humandigestion . It is produced by cells in the duodenum wall, and is secreted from duodenum's glands, thecrypts of Lieberkühn , whenever ingested food enters the duodenum from the stomach. Enteropeptidase has the critical job of turningtrypsinogen (azymogen ) totrypsin , indirectly activating a number of pancreatic digestive enzymes.Enteropeptidase is a
serine protease enzyme (EC number|3.4.21.9). Enteropeptidase is a part of theChymotrypsin -clan of serine proteases, and is structurally similar to these proteins.Reaction
The reaction catalysed by Enteropeptidase:
trypsinogen → trypsin + octapeptide
Enteropeptidase cleaves after Lysine if the Lys is preceded by four Asp and not followed by a Pro. [cite web|url=http://www.neb.com/nebecomm/products/productP8070.asp|title=Enterokinase, light chain (P8070), Proteases, NEB|accessdate=2007-10-04]
Nomenclature
Despite its older name of "enterokinase", the enzyme is not a
kinase . This is because enteropeptidase alters the degree of enzymatic activity its substrate expresses though a proteolytic cleavage reaction. Akinase would do the same byphosphorylation reaction.Genetics
Enteropeptidase is encoded by the "PRSS7" (serine protease-7 gene) or "ENTK" gene on the 21st chromosome (21q21).
Isolated cases of enteropeptidase deficiency have been reported. [cite journal |author=Holzinger A, Maier EM, Bück C, "et al" |title=Mutations in the proenteropeptidase gene are the molecular cause of congenital enteropeptidase deficiency |journal=Am. J. Hum. Genet. |volume=70 |issue=1 |pages=20–5 |year=2002 |pmid=11719902 |doi=]
References
External links
*
Wikimedia Foundation. 2010.