Structure of glycosylated human aminopeptidase NStructure of glycosylated human aminopeptidase N

Structural highlights

5lhd is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.6Å
Ligands:, , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

AMPN_HUMAN Broad specificity aminopeptidase. Plays a role in the final digestion of peptides generated from hydrolysis of proteins by gastric and pancreatic proteases. May play a critical role in the pathogenesis of cholesterol gallstone disease. May be involved in the metabolism of regulatory peptides of diverse cell types, responsible for the processing of peptide hormones, such as angiotensin III and IV, neuropeptides, and chemokines. Found to cleave antigen peptides bound to major histocompatibility complex class II molecules of presenting cells and to degrade neurotransmitters at synaptic junctions. Is also implicated as a regulator of IL-8 bioavailability in the endometrium, and therefore may contribute to the regulation of angiogenesis. Is used as a marker for acute myeloid leukemia and plays a role in tumor invasion. In case of human coronavirus 229E (HCoV-229E) infection, serves as receptor for HCoV-229E spike glycoprotein. Mediates as well human cytomegalovirus (HCMV) infection.[1] [2] [3] [4] [5] [6] [7] [8] [9]

Publication Abstract from PubMed

Cell surface aminopeptidase N (APN) is a membrane-bound ectoenzyme that hydrolyzes proteins and peptides and regulates numerous cell functions. APN participates in tumor cell expansion and motility, and is a target for cancer therapies. Small drugs that bind to the APN active site inhibit catalysis and suppress tumor growth. APN is also a major cell entry receptor for coronavirus, which binds to a region distant from the active site. Three crystal structures that we determined of human and pig APN ectodomains defined the dynamic conformation of the protein. These structures offered snapshots of closed, intermediate and open APN, which represent distinct functional states. Coronavirus envelope proteins specifically recognized the open APN form, prevented ectodomain progression to the closed form and substrate hydrolysis. In addition, drugs that bind the active site inhibited both coronavirus binding to cell surface APN and infection; the drugs probably hindered APN transition to the virus-specific open form. We conclude that allosteric inhibition of APN functions occurs by ligand suppression of ectodomain motions necessary for catalysis and virus cell entry, as validated by locking APN with disulfides. Blocking APN dynamics can thus be a valuable approach to development of drugs that target this ectoenzyme.

Allosteric inhibition of aminopeptidase N functions related to tumor growth and virus infection.,Santiago C, Mudgal G, Reguera J, Recacha R, Albrecht S, Enjuanes L, Casasnovas JM Sci Rep. 2017 Apr 10;7:46045. doi: 10.1038/srep46045. PMID:28393915[10]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Yeager CL, Ashmun RA, Williams RK, Cardellichio CB, Shapiro LH, Look AT, Holmes KV. Human aminopeptidase N is a receptor for human coronavirus 229E. Nature. 1992 Jun 4;357(6377):420-2. PMID:1350662 doi:http://dx.doi.org/10.1038/357420a0
  2. Soderberg C, Giugni TD, Zaia JA, Larsson S, Wahlberg JM, Moller E. CD13 (human aminopeptidase N) mediates human cytomegalovirus infection. J Virol. 1993 Nov;67(11):6576-85. PMID:8105105
  3. Kolb AF, Maile J, Heister A, Siddell SG. Characterization of functional domains in the human coronavirus HCV 229E receptor. J Gen Virol. 1996 Oct;77 ( Pt 10):2515-21. PMID:8887485
  4. Noren K, Hansen GH, Clausen H, Noren O, Sjostrom H, Vogel LK. Defectively N-glycosylated and non-O-glycosylated aminopeptidase N (CD13) is normally expressed at the cell surface and has full enzymatic activity. Exp Cell Res. 1997 Feb 25;231(1):112-8. PMID:9056417 doi:10.1006/excr.1996.3455
  5. Hegyi A, Kolb AF. Characterization of determinants involved in the feline infectious peritonitis virus receptor function of feline aminopeptidase N. J Gen Virol. 1998 Jun;79 ( Pt 6):1387-91. PMID:9634079
  6. Dong X, An B, Salvucci Kierstead L, Storkus WJ, Amoscato AA, Salter RD. 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. J Immunol. 2000 Jan 1;164(1):129-35. PMID:10605003
  7. Pasqualini R, Koivunen E, Kain R, Lahdenranta J, Sakamoto M, Stryhn A, Ashmun RA, Shapiro LH, Arap W, Ruoslahti E. Aminopeptidase N is a receptor for tumor-homing peptides and a target for inhibiting angiogenesis. Cancer Res. 2000 Feb 1;60(3):722-7. PMID:10676659
  8. Seli E, Senturk LM, Bahtiyar OM, Kayisli UA, Arici A. Expression of aminopeptidase N in human endometrium and regulation of its activity by estrogen. Fertil Steril. 2001 Jun;75(6):1172-6. PMID:11384645
  9. van Hensbergen Y, Broxterman HJ, Hanemaaijer R, Jorna AS, van Lent NA, Verheul HM, Pinedo HM, Hoekman K. Soluble aminopeptidase N/CD13 in malignant and nonmalignant effusions and intratumoral fluid. Clin Cancer Res. 2002 Dec;8(12):3747-54. PMID:12473585
  10. Santiago C, Mudgal G, Reguera J, Recacha R, Albrecht S, Enjuanes L, Casasnovas JM. Allosteric inhibition of aminopeptidase N functions related to tumor growth and virus infection. Sci Rep. 2017 Apr 10;7:46045. doi: 10.1038/srep46045. PMID:28393915 doi:http://dx.doi.org/10.1038/srep46045

5lhd, resolution 2.60Å

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