Biology:Alanine aminopeptidase

Short description: Mammalian protein found in Homo sapiens

Generic protein structure example

Membrane alanyl aminopeptidase (EC 3.4.11.2) also known as alanyl aminopeptidase (AAP) or aminopeptidase N (AP-N) is an enzyme that in humans is encoded by the ANPEP gene.

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, feline coronavirus serotype II (FCoV-II), TGEV, PEDV, canine coronavirus genotype II (CCoV-II) as well as several Deltacoronaviruses.

Further reading

• "Human aminopeptidase N is a receptor for human coronavirus 229E". Nature 357 (6377): 420–2. June 1992. doi:10.1038/357420a0. PMID 1350662. Bibcode: 1992Natur.357..420Y. 
• "Separate promoters control transcription of the human aminopeptidase N gene in myeloid and intestinal epithelial cells". The Journal of Biological Chemistry 266 (18): 11999–2007. June 1991. doi:10.1016/S0021-9258(18)99056-3. PMID 1675638. 
• "Variable O-glycosylation of CD13 (aminopeptidase N)". The Journal of Biological Chemistry 266 (7): 4593–7. March 1991. doi:10.1016/S0021-9258(20)64364-2. PMID 1705556. 
• "The human aminopeptidase N gene: isolation, chromosome localization, and DNA polymorphism analysis". Human Genetics 85 (6): 651–4. October 1990. doi:10.1007/BF00193592. PMID 1977688. 
• "Molecular cloning, expression, and chromosomal localization of the gene encoding a human myeloid membrane antigen (gp150)". The Journal of Clinical Investigation 78 (4): 914–21. October 1986. doi:10.1172/JCI112680. PMID 2428842. 
• "Human myeloid plasma membrane glycoprotein CD13 (gp150) is identical to aminopeptidase N". The Journal of Clinical Investigation 83 (4): 1299–307. April 1989. doi:10.1172/JCI114015. PMID 2564851. 
• "Complete amino acid sequence of human intestinal aminopeptidase N as deduced from cloned cDNA". FEBS Letters 238 (2): 307–14. October 1988. doi:10.1016/0014-5793(88)80502-7. PMID 2901990. 
• "Assignment of the human aminopeptidase N (peptidase E) gene to chromosome 15q13-qter". FEBS Letters 239 (2): 305–8. November 1988. doi:10.1016/0014-5793(88)80940-2. PMID 2903074. 
• "Purification and characterization of aminopeptidase N from human plasma". Enzyme 32 (2): 65–75. 1985. doi:10.1159/000469453. PMID 6149934. 
• "Identification of an alanine aminopeptidase in human maternal serum as a membrane-bound aminopeptidase N". Biological Chemistry Hoppe-Seyler 376 (7): 397–400. July 1995. doi:10.1515/bchm3.1995.376.7.397. PMID 7576235. 
• "CD13 (GP150; aminopeptidase-N): predominant functional activity in blood is localized to plasma and is not cell-surface associated". Experimental Hematology 21 (13): 1695–701. December 1993. PMID 7902291. 
• "Cholesterol crystallization-promoting activity of aminopeptidase-N isolated from the vesicular carrier of biliary lipids". FEBS Letters 329 (1–2): 84–8. August 1993. doi:10.1016/0014-5793(93)80199-5. PMID 8102610. 
• "CD13 (human aminopeptidase N) mediates human cytomegalovirus infection". Journal of Virology 67 (11): 6576–85. November 1993. doi:10.1128/JVI.67.11.6576-6585.1993. PMID 8105105. 
• "Characterization of functional domains in the human coronavirus HCV 229E receptor". The Journal of General Virology 77 (10): 2515–21. October 1996. doi:10.1099/0022-1317-77-10-2515. PMID 8887485. 
• "Defectively N-glycosylated and non-O-glycosylated aminopeptidase N (CD13) is normally expressed at the cell surface and has full enzymatic activity". Experimental Cell Research 231 (1): 112–8. February 1997. doi:10.1006/excr.1996.3455. PMID 9056417. 
• "Identification of residues critical for the human coronavirus 229E receptor function of human aminopeptidase N". The Journal of General Virology 78 (11): 2795–802. November 1997. doi:10.1099/0022-1317-78-11-2795. PMID 9367365. 
• "Characterization of determinants involved in the feline infectious peritonitis virus receptor function of feline aminopeptidase N". The Journal of General Virology 79 (6): 1387–91. June 1998. doi:10.1099/0022-1317-79-6-1387. PMID 9634079. 
• "Modification of the amino terminus of a class II epitope confers resistance to degradation by CD13 on dendritic cells and enhances presentation to T cells". Journal of Immunology 164 (1): 129–35. January 2000. doi:10.4049/jimmunol.164.1.129. PMID 10605003. 
• "Aminopeptidase N is a receptor for tumor-homing peptides and a target for inhibiting angiogenesis". Cancer Research 60 (3): 722–7. February 2000. PMID 10676659. 
• "Basolateral sorting signals differ in their ability to redirect apical proteins to the basolateral cell surface". The Journal of Biological Chemistry 275 (13): 9290–5. March 2000. doi:10.1074/jbc.275.13.9290. PMID 10734069. 

External links

• The MEROPS online database for peptidases and their inhibitors: M01.001
• CD13+Antigens at the US National Library of Medicine Medical Subject Headings (MeSH)
• Human ANPEP genome location and ANPEP gene details page in the UCSC Genome Browser.