Triple Point Biologics' Aspartic Proteinases recombinant catalog covers eleven members of the pepsin-fold clan (MEROPS clan AA), including BACE1, BACE2, cathepsin D, cathepsin E, pepsin A, renin, napsin A, napsin B, and the presenilin family. Aspartic proteinases are endopeptidases defined by a bilobed structure in which two aspartate residues cooperate to activate a water molecule for nucleophilic attack on the scissile peptide bond. The class spans subcellular compartments—lysosomes (cathepsin D, cathepsin E), the secretory pathway (BACE1, BACE2), the gastric lumen (pepsin A), and the circulation (renin)—and spans pH optima from approximately 2 (pepsin A) to 7 (BACE1). Members of this class have been extensively investigated in Alzheimer's disease (BACE1-mediated cleavage of APP), lysosomal storage and antigen processing (cathepsin D, cathepsin E), blood pressure regulation via the renin–angiotensin system, and pulmonary surfactant processing (napsin A). Presenilin 1 and 2, atypical intramembrane aspartyl proteases, are characterized in published studies of γ-secretase complex assembly and familial Alzheimer's disease.

All recombinant proteins in this collection are produced in HEK293 cells to preserve mammalian glycosylation and disulfide-bond formation relevant to native folding. Each catalog entry is paired with a matched rabbit polyclonal antibody raised in the same laboratory—Triple Point Biologics has produced proteinase and inhibitor antibodies continuously since 1994—providing antigen-matched reagents for orthogonal detection. Antibodies in this series are validated for Western blot and IHC; cross-reactivity with non-human orthologs is indicated per entry as predicted (by sequence homology) or validated (by direct testing). Where immunogen boundaries are defined, they are stated in the individual product datasheets (e.g., residues raised against a defined recombinant domain) rather than as generic descriptors.

Typical applications for this protein collection include substrate-cleavage and inhibitor-profiling assays, FRET-based activity measurements in reconstituted systems, and use as positive controls in immunoassay development and Western blot standardization. For guidance on designing fluorogenic substrate assays compatible with these enzymes, see the Protease Activity Assay Guide. Researchers optimizing immunoassay panels or antibody validation workflows may also consult the Recombinant Protein Positive Controls Guide. Specific activity, purity by SDS-PAGE, and endotoxin values are reported on each product page.