Digests TAMe (p-toluene arginine methyl ester), but not ethyl N-benzoyl-L-tyrosinate (BTEE). Preferential cleavage: Arg-|-Xaa, Lys-|-Xaa. Inhibited by the serine protease inhibitor phenylmethylsulfonyl, and trypsin inhibitors soybean trypsin inhibitor and tosyllysine chloromethyl ketone. Not inhibited by dithiothreitol, a cysteine protease inhibitor. Causes an allergic reaction in human. Binds to IgE of patients allergic to storage mite T.putrescentiae (PubMed:19339798, PubMed:20197679, PubMed:20683648). Binds to IgE in 58% of the 110 patients tested (PubMed:19339798). Binds to IgE in 50% of the 44 elderly patients (aged 70-90) tested (PubMed:20197679). Binds to IgE in 45% of the 22 young adult rhinitis patients tested allergic to mites (both T.putrescentiae and D.pteronyssinus). This protein might be a T.putrescentiae specific allergen since it cannot be absorbed by group 3 allergen (Der p 3) of D.pteronyssinus in the IgE immunoblot inhibition assay (PubMed:20683648). Is able to induce histamine release from human basophils (PubMed:19339798). Belongs to the peptidase S1 family.