Granzyme K Protein, Human (His)

Granzyme K is a serine protease, belonging to the granzyme family of proteins. Granzyme K is similar to Granzyme A in that they are the only granzymes that display tryptase-like activity. Granzyme K induces cell death by single-stranded nicking of the chromosomal DNA by cleaving the same components of the endoplasmic reticulum-associated SET complex. Granzyme K may provide a backup and failsafe mechanism for Granzyme A with redundant specificity. Natural killer (NK) cells and cytotoxic T lymphocytes (CTLs) store Granzyme K in their granules which they release to induce apoptosis in target cells. Granzyme K is primarily expressed in thymus, lung, spleen and peripheral blood leukocytes. Granzyme K shows significant connections to inflammatory conditions and autoimmune diseases such as rheumatoid arthritis. In autoimmune disorders granzyme K works in combination with proteins like perforin which facilitates entry of granzymes into the cell to stimulate apoptosis^[1][2].

Granzyme K Protein, Human (His) cleaves synthetic thiobenzyl ester substrates after Lys and Arg with k_cat/K_m values of 3.7 × 10⁴ and 4.4 × 10⁴/m·s, respectively^[1].
Granzyme K Protein, Human (His)'s (3 nM; 60 min) activity can be inhibited by the synthetic compounds Phe-Pro-Arg-chloromethyl ketone, PMSF (HY-B0496), PefablocSC, Benzamidine (HY-125913), and the Kunitz-type inhibitor Aprotinin (HY-P0017)^[1].
Granzyme K Protein, Human (His)'s (3 nM; 15 min) activity can be inhibited by the plasma-derived inter-α-trypsin inhibitor complex, its bikunin subunit, and the second carboxyl-terminal Kunitz-type domain of bikunin with K_i values of 64, 50, and 22 nm, respectively^[1].
Granzyme K Protein, Human (His) (1 μM; 5-60 min) is markedly more efficient in cleaving heterogeneous ribonuclear protein K than Granzyme A^[2].
Granzyme K Protein, Human (His) (5-100 nM; 2 h) cleaves the microtubule network protein β-tubulin after two distinct Arg residues^[2].