Triple Point Biologics' Serine Proteinases recombinant catalog covers more than 40 distinct enzymes across the major mammalian serine proteinase families, including kallikreins (KLK1–15), granzymes A, B, H, and K, complement proteases MASP-1/2/3, HTRA family members, type II transmembrane serine proteinases (TMPRSS2/3/4 and related), neutrophil elastase, chymase, tryptase, furin, PCSK family convertases, and plasminogen. Serine proteinases constitute one of the largest and most functionally diverse protease classes in vertebrates, unified by a catalytic triad (Ser-His-Asp) housed within a chymotrypsin- or subtilisin-fold scaffold. They function as central effectors and regulators in proteolytic cascades governing coagulation, complement activation, fibrinolysis, immune cell cytotoxicity, and prohormone processing. Their activities are tightly controlled by cognate serpin and Kunitz-type inhibitors, making recombinant forms essential reference reagents for dissecting substrate specificity, inhibitor kinetics, and zymogen activation mechanisms.

All recombinant serine proteinases in this collection are produced in HEK293 expression systems to maximize the fidelity of post-translational processing relevant to the mature, secreted, or membrane-anchored forms characterized in the literature. Each recombinant protein is paired with a matching rabbit polyclonal antibody raised in Triple Point Biologics' own laboratory—the same laboratory that has been producing proteinase and inhibitor antibodies continuously since 1994. Antibodies are validated for Western blot and IHC; cross-reactivity with orthologous species proteins is indicated as validated or predicted on individual product pages based on sequence identity data. This one-source pairing allows direct use of the recombinant as a defined positive control for antibody validation in the same experimental system.

Catalog members have been applied across a broad range of research contexts: kallikreins and TMPRSS2 are characterized in published studies of prostate cancer progression and SARS-CoV-2 cell entry; granzymes and complement MASPs are investigated in lymphocyte cytotoxicity and innate immune pathway research; furin and PCSK convertases are studied in proprotein processing and lipid metabolism models. For guidance on setting up functional enzyme activity assays with these proteins, see the Triple Point Biologics Protease Activity Assay Guide. For best practices on using recombinant proteins as immunoassay positive controls, refer to the Recombinant Protein Positive Controls Guide. All proteins are supplied for research use only.