This gene encodes a trypsinogen, which is a member of the trypsin family of serine proteases. This enzyme is secreted by the pancreas and cleaved to its active form in the small intestine. It is active on peptide linkages involving the carboxyl group of lysine or arginine. Mutations in this gene are associated with hereditary pancreatitis. This gene and several other trypsinogen genes are localized to the T cell receptor beta locus on chromosome 7. [provided by RefSeq, Jul 2008],catalytic activity:Preferential cleavage: Arg-|-Xaa, Lys-|-Xaa.,caution:Tyr-154 was proposed to be phosphorylated (PubMed:8683601) but it has been shown (PubMed:17087724) to be sulfated instead. Phosphate and sulfate groups are similar in mass and size, and this can lead to erroneous interpretation of the results.,cofactor:Binds 1 calcium ion per subunit.,disease:Defects in PRSS1 are a cause of hereditary pancreatitis (HPC) [MIM:167800]; also known as chronic pancreatitis (CP). HPC is an autosomal dominant disease characterized by the presence of calculi in pancreatic ducts. It causes severe abdominal pain attacks.,function:Has 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. The single-chain form is more active than the two-chain form against all of these substrates.,mass spectrometry: PubMed:8683601,PTM:Occurs in a single-chain form and a two-chain form, produced by proteolytic cleavage after Arg-122.,similarity:Belongs to the peptidase S1 family.,similarity:Contains 1 peptidase S1 domain.,