NPEPPS - Puromycin-sensitive aminopeptidase - human protein (Function)
Home Recent activites arrow-down favorite My favorites arrow-down favorite My labels arrow-down Downloads
Back to ...  
Publication View

NPEPPS »  Puromycin-sensitive aminopeptidase   [ EC ]  (PSA)
Protein also known as:  Cytosol alanyl aminopeptidase (AAP-S).
Gene name:  NPEPPS
Family name: Peptidase M1
Entry whose protein(s) existence is based on evidence at protein level
extend overview
1 29 1


 show evidences
Aminopeptidase with broad substrate specificity for several peptides. Involved in proteolytic events essential for cell growth and viability. May act as regulator of neuropeptide activity. Plays a role in the antigen-processing pathway for MHC class I molecules. Involved in the N-terminal trimming of cytotoxic T-cell epitope precursors. Digests the poly-Q peptides found in many cellular proteins. Digests tau from normal brain more efficiently than tau from Alzheimer disease brain.  
  • CuratedUniProtKB
GO molecular function 
Aminopeptidase activitydefinition[GO:0004177]  
  • IEAUniProtKB KW
Metallopeptidase activitydefinition[GO:0008237]  
  • IEAUniProtKB KW
Zinc ion bindingdefinition[GO:0008270] silver  
  • IEAInterPro 2 GO
GO biological process 
Cellular response to hypoxiadefinition[GO:0071456]  
  • IDAUniProtKB
  • IEAUniProtKB KW
Enzymatic activity 
This protein acts as an enzyme. It is known to catalyze the following reaction
EC Release of an N-terminal amino acid, preferentially alanine, from a wide range of peptides, amides and arylamides.  
  • CuratedUniProtKB
It requires the following cofactor
Binds 1 zinc ion per subunit (By similarity).  
  • CuratedUniProtKB
It is regulated in the following manner
Strongly inhibited by bestatin, leuhistin, actinonin, amastatin, 1,10-phenanthroline, DFP, PCMBS, Zn(2+), Cd(2+), Co(2+), Cu(2+), Hg(2+), EDTA and puromycin. Not inhibited by PMSF, and only slightly inhibited by leupeptin and aprotinin. Activity is increased by Mg(2+) and Ca(2+).  
  • CuratedUniProtKB
More information is available from:
According to Reactome, this protein belongs to the following pathway:
Antigen processing: Ubiquitination & Proteasome degradation  REACT_75842  

Biophysicochemical properties

Kinetic parameters
KM 182 uM for Ala-MCA
KM 220 uM for Lys-MCA
KM 167 uM for Phe-MCA
KM 91 uM for Leu-MCA
KM 0.47 mM for Pro-p-NA
KM 2.20 mM for Lys-p-NA
KM 0.25 mM for Leu-p-NA
KM 0.80 mM for Met-p-NA
KM 189 uM for Met-MCA
KM 0.21 mM for Val-p-NA
KM 0.27 mM for Ala-p-NA
pH Optimum pH is 7.5. Stable from pH 5.0 to 8.0.
Temperature Stable up to 40 degrees Celsius.


Molecular function 
Aminopeptidase  definition   [KW-0031]
Hydrolase  definition   [KW-0378]
Metalloprotease  definition   [KW-0482]
Protease  definition   [KW-0645]
Technical term 
Reference proteome  definition   [KW-1185]

Further external links

GeneWiki: NPEPPS
GenomeRNAi: 9520
PRO: PR:P55786