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EC Number

Catalytic Site Atlas

CSA LITERATURE entry for 8pch

E.C. namecathepsin H
SpeciesSus scrofa (Pig)
E.C. Number (IntEnz)
CSA Homologues of 8pchThere are 185 Homologs
CSA Entries With UniProtID O46427
CSA Entries With EC Number
PDBe Entry 8pch
PDBSum Entry 8pch
MACiE Entry 8pch

Literature Report

IntroductionCathepsin H is a lysosomal cysteine protease, involved in intracellular protein degradation. It is the only known mono-aminopeptidase in the papain-like family and is reported to be involved in tumor metastasis. The enzyme is a relatively abundant protease involved in intracellular protein degradation. It has been proposed that the levels of Cathepsin increase during disease states.
Cathepsin H is an aminopeptidase, cleaving a single N-terminal residue from a polypeptide chain. It has been shown that Cathepsin H also exhibits endopeptidase activity. The mature protein consists of three fragments; the N-terminal heavy and C-terminal light chains, and an octapeptide called the mini-chain.
MechansimThe active site triad ( CYS 25, HIS 159, GLN 19) is found in a cleft found running across the top of the molecule. The backbone and sidechains of the catalytic residues are found at positions usual for a papain-like enzyme. The only exception is the HIS 159 imidazole ring which in contrasts to all other known structures of cysteine proteases - does not form a thiolate-imidazolium ion pair with CYS 25.

Catalytic Sites for 8pch

Annotated By Reference To The Literature - Site 2 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription

Literature References

Guncar G
Crystal structure of porcine cathepsin H determined at 2.1 A resolution: location of the mini-chain C-terminal carboxyl group defines cathepsin H aminopeptidase function.
Structure 1998 6 51-61
PubMed: 9493267