KEGG   ENZYME: 3.4.18.1Help
Entry
EC 3.4.18.1                 Enzyme                                 

Name
cathepsin X;
cathepsin B2;
cysteine-type carboxypeptidase;
cathepsin IV;
cathepsin Z;
acid carboxypeptidase;
lysosomal carboxypeptidase B
Class
Hydrolases;
Acting on peptide bonds (peptidases);
Cysteine-type carboxypeptidases
BRITE hierarchy
Reaction(IUBMB)
Release of C-terminal amino acid residues with broad specificity, but lacks action on C-terminal proline. Shows weak endopeptidase activity
Comment
Cathepsin X is a lysosomal cysteine peptidase of family C1 (papain family). The pH optimum is dependent on the substrate and is 5.0 for the carboxypeptidase activity. Unstable above pH 7.0. Compound E-64, leupeptin and antipain are inhibitors, but not cystatin C. Cathepsin X is ubiquitously distributed in mammalian tissues. The propeptide is extremely short (38 amino acid residues) and the proenzyme is catalytically active. Human gene locus: 20q13.
History
EC 3.4.18.1 created 1981, modified 2000
Orthology
K08568  
cathepsin X
Genes
HSA: 
1522(CTSZ)
PTR: 
736240(CTSZ)
PPS: 
100978982(CTSZ)
GGO: 
101135556(CTSZ)
PON: 
100445547(CTSZ)
NLE: 
100605843(CTSZ)
MCF: 
102118566(CTSZ)
CJC: 
100409242(CTSZ)
MMU: 
64138(Ctsz)
RNO: 
252929(Ctsz)
CGE: 
100689392(Ctsz)
HGL: 
101720244(Ctsz)
TUP: 
102500911(CTSZ)
CFA: 
611983(CTSZ)
AML: 
UMR: 
103670963(CTSZ)
FCA: 
101087983(CTSZ)
PTG: 
BTA: 
404187(CTSZ)
BOM: 
102265582(CTSZ)
PHD: 
102340046(CTSZ)
CHX: 
102175417(CTSZ)
OAS: 
SSC: 
100141405(CTSZ)
CFR: 
102515641(CTSZ)
BACU: 
103013660(CTSZ)
LVE: 
103085943(CTSZ)
ECB: 
100056600(CTSZ)
MYB: 
102242643(CTSZ)
MYD: 
102770003(CTSZ)
PALE: 
102884357(CTSZ)
MDO: 
100027054(CTSZ)
SHR: 
100927306(CTSZ)
OAA: 
100080444(CTSZ)
GGA: 
419311(CTSZ)
MGP: 
APLA: 
101804246(CTSZ)
TGU: 
FAB: 
101818266(CTSZ)
PHI: 
102103433(CTSZ)
FPG: 
101921980(CTSZ)
FCH: 
102059599(CTSZ)
CLV: 
102084569(CTSZ)
ASN: 
102384346(CTSZ)
AMJ: 
102561646(CTSZ)
PSS: 
102447291(CTSZ)
CMY: 
102934401(CTSZ)
ACS: 
PBI: 
XLA: 
XTR: 
100127597(ctsz)
DRE: 
450022(ctsz)
TRU: 
MZE: 
OLA: 
XMA: 
LCM: 
102354050(CTSZ)
CMK: 
103171603(ctsz)
BFO: 
SPU: 
CEL: 
CBR: 
CBG04105(Cbr-cpz-1) CBG06727(Cbr-cpz-2)
BMY: 
LOA: 
TSP: 
HRO: 
LGI: 
NVE: 
HMG: 
AQU: 
PPP: 
CRE: 
VCN: 
OLU: 
OTA: 
BPG: 
MIS: 
MPP: 
CSL: 
CVR: 
MBR: 
DDI: 
DPP: 
DFA: 
TET: 
PTM: 
PTI: 
TPS: 
PIF: 
EHX: 
GTT: 
NGR: 
 » show all
Taxonomy
Reference
1  [PMID:10504234]
  Authors
Nagler DK, Zhang R, Tam W, Sulea T, Purisima EO, Menard R
  Title
Human cathepsin X: A cysteine protease with unique carboxypeptidase activity.
  Journal
Biochemistry. 38 (1999) 12648-54.
  Sequence
[hsa:1522]
Reference
2  [PMID:9738465]
  Authors
Nagler DK, Menard R.
  Title
Human cathepsin X: a novel cysteine protease of the papain family with a very short proregion and unique insertions.
  Journal
FEBS. Lett. 434 (1998) 135-9.
  Sequence
[hsa:1522]
Reference
3  [PMID:9642240]
  Authors
Santamaria I, Velasco G, Pendas AM, Fueyo A, Lopez-Otin C.
  Title
Cathepsin Z, a novel human cysteine proteinase with a short propeptide domain and a unique chromosomal location.
  Journal
J. Biol. Chem. 273 (1998) 16816-23.
  Sequence
[hsa:1522]
Reference
4  [PMID:577]
  Authors
McDonald JK, Ellis S.
  Title
On the substrate specificity of cathepsins B1 and B2 including a new fluorogenic substrate for cathepsin B1.
  Journal
Life. Sci. 17 (1975) 1269-76.
Reference
5  [PMID:1122298]
  Authors
Otto K, Riesenkonig H.
  Title
Improved purification of cathepsin B1 and cathepsin B2.
  Journal
Biochim. Biophys. Acta. 379 (1975) 462-75.
Reference
6  [PMID:4429705]
  Authors
Ninjoor V, Taylor SL, Tappel AL.
  Title
Purification and characterization of rat liver lysosomal cathepsin B2.
  Journal
Biochim. Biophys. Acta. 370 (1974) 308-21.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
37217-21-3

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