| Name | Peptidase family M13 (neprilysin family) |
|---|
| Family type peptidase | M13.001 - neprilysin (Homo sapiens), MEROPS Accession MER0001050 (peptidase unit: 52-750) |
| Content of family | Peptidase family M13 contains metalloendopeptidases restricted to action on substrates smaller than proteins. |
| History |
Identifier created: Biochem.J. 290:205-218 (1993)
Neprilysin (M13.001), a neutral-acting metalloendopeptidase, was discovered in brush border membranes by Kenny and colleagues (e.g. Kerr & Kenny, 1974; Kerr & Kenny, 1974). It was for a long time the only known peptidase in family M13, but additional homologues are now known, principally from animals and bacteria. |
| Catalytic type | Metallo |
| Active site residues | H584 E585 H588 E647 D651 |
| Active site | There is a HEXXH motif, in which the His residues are ligands of a zinc atom and the Glu has a catalytic role. There is also a more C-terminal Glu residue that is the third ligand of the zinc atom (see the Alignment). Residues involved in substrate binding in neprilysin are Val541, Asn542, Ala543, His711 and Arg717 (Oefner et al., 2000). |
| Activities and specificities | The enzymes appear to be synthesised in active form; there are no proenzymes. Probably all peptidases in family M13 are restricted to acting on substrates of not more than about 40 residues. Substrates of neprilysin include bioactive peptides such as the enkephalins, substance P, endothelin, bradykinin and atrial natriuretic factor, but the other mammalian enzymes have more restricted activities. For example, endothelin-converting enzyme 1 (M13.002) is very selective for the cleavage of Trp Val/Ile in the 'big endothelin' precursors of endothelin 1 (Turner & Murphy, 1996; Ahn & Johnson, 2004), and human recombinant endopeptidase PHEX (M13.091) has a strict S1" specificity for acidic residues, preferably Asp (Campos et al., 2003). |
| Inhibitors | Metal chelating agents such as 1,10-phenanthroline inhibit, as is expected for metallopeptidases. Phosphoramidon is a potent inhibitor. There has been much work towards the development of selective inhibitors of neprilysin and endothelin-converting enzyme as possible drugs (see Literature for the individual enzymes). There is little evidence of physiological inhibitors of these peptidases. |
| Molecular structure | The structure of neprilysin may be typical for the family. From the N-terminus, there is a short (27 residues) cytoplasmic tail followed by a hydrophobic segment (23 residues) that anchors the enzyme to the cell membrane. The bulk of the protein, located extracellularly, comprises two domains that enclose a large central cavity containing the active site. The more N-terminal of the domains has a fold reminiscent of that of thermolysin and contains the active site residues. The second domain may well serve to control access of substrates to the active site and prevent cleavage of proteins. The thermolysin-like fold of the catalytic domain is the reason for the assignment ot clan MA (subclan E). Neprilysin is glycosylated. |
| Clan | MA |
| Subclan | MA(E) |
| Basis of clan assignment | Protein fold of the peptidase unit for members of this family resembles that of thermolysin, the type example for clan MA. |
| Biological functions | The enzymes act outside animal cells to degrade or convert polypeptide substrates. In bacteria they are presumed to have a nutritional role. |
| Pharmaceutical and biotech relevance | Activities of neprilysin such as the destruction of enkephalins, and the generation of endothelin 1 by endothelin-converting enzyme 1, make these enzymes potential drug targets, and there has been a great deal of work on the development of inhibitors. |
| Statistics for family M13 | Sequences: | 12551 |
| Identifiers: | 49 |
| Identifiers with PDB entries: | 4 |
| Downloadable files |
Sequence library (FastA format) |
| Sequence alignment (FastA format) |
| Phylogenetic tree (Newick format) |
| Peptidases and Homologues |
MEROPS ID |
Structure |
| neprilysin | M13.001 | Yes |
| endothelin-converting enzyme 1 | M13.002 | Yes |
| endothelin-converting enzyme 2 | M13.003 | Yes |
| oligopeptidase O1 | M13.004 | - |
| oligopeptidase O3 | M13.005 | - |
| endothelin-converting enzyme-like 1 endopeptidase | M13.007 | - |
| neprilysin-2 | M13.008 | - |
| Zmp1 peptidase (Mycobacterium-type) | M13.009 | Yes |
| oligopeptidase O2 | M13.010 | - |
| MEP peptidase (nematode) | M13.011 | - |
| Nep2 peptidase (insect) | M13.012 | - |
| NEP-1 peptidase (Caenorhabditis sp.) | M13.013 | - |
| neprilysin-4 (Drosophila melanogaster) | M13.014 | - |
| NEP-2 peptidase (Caenorhabditis sp.) | M13.015 | - |
| T25B6.2 g.p. (Caenorhabditis elegans) | M13.016 | - |
| oligopeptidase O (Porphyromonas gingivalis) | M13.017 | - |
| Kell blood-group peptidase | M13.090 | - |
| PHEX peptidase | M13.091 | - |
| similar to Kell blood group protein (Rattus norvegicus) | M13.950 | - |
| CG3775 g.p. (Drosophila melanogaster) | M13.A01 | - |
| CG6265 g.p. (Drosophila melanogaster) | M13.A02 | - |
| CG8550 g.p. (Drosophila melanogaster) | M13.A03 | - |
| CG14526 g.p. (Drosophila melanogaster) | M13.A04 | - |
| CG14527 g.p. (Drosophila melanogaster) | M13.A05 | - |
| CG14528 g.p. (Drosophila melanogaster) | M13.A06 | - |
| CG14529 g.p. (Drosophila melanogaster) | M13.A07 | - |
| CG5527 g.p. (Drosophila melanogaster) | M13.A08 | - |
| CG8358 g.p. (Drosophila melanogaster) | M13.A09 | - |
| CG9508 g.p. (Drosophila melanogaster) | M13.A10 | - |
| CG9507 g.p. (Drosophila melanogaster) | M13.A11 | - |
| CG9505 g.p. (Drosophila melanogaster) | M13.A12 | - |
| CG3239 g.p. (Drosophila melanogaster) | M13.A13 | - |
| Nep3 protein (Drosophila melanogaster) | M13.A14 | - |
| CG5894 g.p. (Drosophila melanogaster) | M13.A15 | - |
| neprilysin-11 (Caenorhabditis elegans) | M13.A16 | - |
| K02F6.9 g.p. (Caenorhabditis elegans) | M13.A17 | - |
| T06D4.3 g.p. (Caenorhabditis elegans) | M13.A18 | - |
| F54F11.2 g.p. domain 1 (Caenorhabditis elegans) | M13.A19 | - |
| F54F11.2 g.p. domain 2 (Caenorhabditis elegans) | M13.A20 | - |
| C49D10.10 g.p. (Caenorhabditis elegans) | M13.A21 | - |
| F18A12.6 g.p. (Caenorhabditis elegans) | M13.A22 | - |
| F18A12.4 g.p. (Caenorhabditis elegans) | M13.A23 | - |
| F18A12.1 g.p. (Caenorhabditis elegans) | M13.A24 | - |
| F39E9.4 g.p. (Caenorhabditis elegans) | M13.A25 | - |
| F26G1.6 g.p. (Caenorhabditis elegans) | M13.A26 | - |
| ZK1248.1 g.p. (Caenorhabditis elegans) | M13.A27 | - |
| ZK970.1 g.p. (Caenorhabditis elegans) | M13.A28 | - |
| Y116A8C.4 g.p. (Caenorhabditis elegans) | M13.A30 | - |
| neprilysin-21 (Caenorhabditis elegans) | M13.A31 | - |
| Family M13 non-peptidase homologues | non-peptidase homologue | - |
| Family M13 unassigned peptidases | unassigned | - |
