Anti-serine protease 1 antibodies are used in the immunodetection of the protein encoded by the PRSS1 gene. In humans, the canonical protein has a reported length of 247 amino acid residues and a mass of 26.6 kDa. It is known to be a secreted protein. A member of the Peptidase S1 protein family, it is known to have activity against the synthetic substrates Boc-Phe-Ser-Arg-Mec, Boc-Leu-Thr-Arg-Mec, Boc-Gln-Ala-Arg-Mec and Boc-Val-Pro-Arg-Mec. Post-translational modifications have been described, including protein cleavage. Other names for this target antigen include TRY1, TRY4, TRYP1, TCR V beta 4.1, anionic trypsin I, beta-trypsin, cationic trypsinogen, and TRP1.