Triple Point Biologics' Serine Proteinases antibody catalog covers more than 40 targets across the principal mammalian serine proteinase families, including kallikreins (KLK1–15), granzymes (A, B, H, K), complement MASPs (MASP-1, -2, -3), HTRA proteases, type II transmembrane serine proteases (TMPRSS2, -3, -4), neutrophil elastase, mast cell chymase and tryptase, furin, the proprotein convertase subtilisin/kexin (PCSK) family, and plasminogen. Serine proteinases are defined by a conserved Ser-His-Asp catalytic triad and constitute one of the largest and mechanistically best-characterized protease classes in vertebrates. They function across a wide range of physiological processes—coagulation and fibrinolysis, complement activation, antigen-specific cytotoxicity, kallikrein-kinin signaling, extracellular matrix remodeling, and regulated zymogen processing—making them central research targets in hemostasis, innate immunity, neutrophil and mast cell biology, prostate cancer, and respiratory virus entry (TMPRSS2, furin).

TPB has produced polyclonal antibodies against proteinases and their inhibitors continuously since 1994. All antibodies in this collection are raised in rabbit against recombinant or synthetic epitopes selected to avoid regions of high homology between paralogs; for example, kallikrein reagents are typically raised against non-catalytic domain segments or pro-peptide sequences to maximize isoform selectivity. Each antibody is routinely validated by reducing SDS-PAGE Western blot and, where tissue distribution supports it, by immunohistochemistry (IHC) on FFPE sections; immunofluorescence (IF) data are available for selected targets. Cross-reactivity with closely related family members is annotated as validated or predicted based on sequence alignment, not assumed. Every antibody in this catalog is matched to a corresponding recombinant protein produced in-house from the same construct used for immunization, providing a structurally consistent positive control for each assay. See our quality and validation standards and the full recombinant protein catalog for details.

These reagents are used in functional protease-activity workflows, inhibitor-screening panels, and expression-profiling studies across a range of sample types including human plasma, bronchoalveolar lavage, tumor lysates, and bone marrow isolates. For guidance on assay design, consult our protease activity assay guide, the recombinant protein positive controls guide, and the protease inhibitor screening guide. Individual target pages include species cross-reactivity data, recommended dilution ranges, and lot-specific validation blots.