Active Granzyme M (GZMM)

GZMM (Granzyme M) is one of the neutral serine proteases, which is specifically expressed by NK cells and mediates a novel major and perforin-dependent cell death pathway. Granzyme M has been proven to targets a-Tubulin and disorganizes the microtubule network, besides, Ezrin has also been identified as a substrate of GZMM. Human granzyme M is synthesized as a precursor (264 residues) with a signal peptide (residues 123), a propeptide (residues 24-25) and a mature chain (residues 26-257). The purified recombinant human Granzyme M consists of residues 26 to 257 which activity was measured by its ability to cleaves a thioester substrate Z-Lys-SBzl•HCl. The reaction was performed in 0.05 M Tris, 0.15 M NaCl, 0.01% Triton X-100, pH 8.0 (assay buffer), initiated by addition 50 μL of various concentrations of GZMM (diluted by assay buffer) to 50 µL of 1.2 mM substrate and DTNB mixture. The final well serves as a negative control with no GZMM, replace with 50 μL assay buffer. Incubated at 25℃ for 5min, then read at a wavelength of 405 nm. The specific activity of recombinant human Granzyme M is >80 pmol/min/µg.