Membrane alanyl aminopeptidase () also known as alanyl aminopeptidase (AAP) or aminopeptidase N (AP-N) is an
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
that in humans is encoded by the ANPEP
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
Aminopeptidase N is located in the small-intestinal and renal microvillar membrane, and also in other plasma membranes. In the small intestine aminopeptidase N plays a role in the final digestion of peptides generated from hydrolysis of proteins by gastric and pancreatic proteases. Its function in proximal tubular epithelial cells and other cell types is less clear. The large extracellular carboxyterminal domain contains a pentapeptide consensus sequence characteristic of members of the zinc-binding metalloproteinase superfamily. Sequence comparisons with known enzymes of this class showed that CD13 and aminopeptidase N are identical. The latter enzyme was thought to be involved in the metabolism of regulatory peptides by diverse cell types, including small intestinal and renal tubular epithelial cells, macrophages, granulocytes, and synaptic membranes from the CNS. Defects in this gene appear to be a cause of various types of leukemia or lymphoma.
AAP is also used by some viruses as a receptor to which these viruses bind to and then enter cells. It is a receptor for
human coronavirus 229E
Human coronavirus 229E (HCoV-229E, ''Alphacoronavirus chicagoense'') is a species of coronavirus which infects humans and bats. It is an Viral envelope, enveloped, Sense (molecular biology), positive-sense, RNA, single-stranded RNA virus which en ...
,
feline coronavirus
Feline coronavirus (FCoV) is a positive-stranded RNA virus that infects cats worldwide. It is a coronavirus of the species ''Alphacoronavirus suis'', which includes canine coronavirus (CCoV) and porcine transmissible gastroenteritis coronaviru ...
serotype II (FCoV-II),
TGEV
Transmissible gastroenteritis virus or Transmissible gastroenteritis coronavirus (TGEV) is a coronavirus which infects pigs. It is an enveloped, positive-sense, single-stranded RNA virus which enters its host cell by binding to the APN recep ...
,
PEDV
Porcine epidemic diarrhea virus (PED virus or PEDV) is a coronavirus that infects the cells lining the small intestine of a pig, causing porcine epidemic diarrhoea, a condition of severe diarrhea and dehydration. Older hogs mostly get sick and l ...
,
canine coronavirus
Canine coronavirus (CCoV) is an enveloped, positive-sense, single-stranded RNA virus which is a member of the species ''Alphacoronavirus suis''. It causes a highly contagious intestinal disease worldwide in dogs. The infecting virus enters it ...
genotype II (CCoV-II) as well as several
Deltacoronaviruses.
References
Further reading
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External links
* The
MEROPS
MEROPS is an online database for peptidases (also known as proteases, proteinases and proteolytic enzymes) and their inhibitors. The classification scheme for peptidases was published by Rawlings & Barrett in 1993, and that for protein inhibito ...
online database for peptidases and their inhibitors
M01.001
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Biomarkers
EC 3.4.11
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