Cathepsin H Is an Additional Convertase of Pro-granzyme B

Porcine spleen cathepsin B is an exopeptidase.

The major cathepsin B isozyme CB-I purified from porcine spleens was studied for its specificity against various peptide and denatured protein substrates. The enzyme degraded all the peptide substrates by an exopeptidase activity. The substrates were degraded mainly by a dipeptidyl carboxypeptidase activity of the enzyme except for angiotensin I, from which a COOH-terminal leucine residue was r...

Interaction of perforin and granzyme B and HTLV-1 viral factors is associated with ATL development

Objective(s): Human T cell leukaemia virus type 1 (HTLV-1) is associated with adult T cell leukaemia (ATL), a malignant lymphoproliferative disease that infects CD4 T cells. It is not clear why the majority of HTLV-1-infected individuals remain asymptomatic carries (ACs) and a minority develop ATL. Cellular immune response has a critical role in ATL and destroys malign...

Involvement of Microglial Cathepsin B in Pro - Interleukin -

Granzyme M is a regulatory protease that inactivates proteinase inhibitor 9, an endogenous inhibitor of granzyme B.

Granzyme M is a trypsin-fold serine protease that is specifically found in the granules of natural killer cells. This enzyme has been implicated recently in the induction of target cell death by cytotoxic lymphocytes, but unlike granzymes A and B, the molecular mechanism of action of granzyme M is unknown. We have characterized the extended substrate specificity of human granzyme M by using pur...

Residual active granzyme B in cathepsin C–null lymphocytes is sufficient for perforin-dependent target cell apoptosis

Cathepsin C activates serine proteases expressed in hematopoietic cells by cleaving an N-terminal dipeptide from the proenzyme upon granule packaging. The lymphocytes of cathepsin C-null mice are therefore proposed to totally lack granzyme B activity and perforin-dependent cytotoxicity. Surprisingly, we show, using live cell microscopy and other methodologies, that cells targeted by allogenic C...