The Molecular Biology of Lithostathine (Pancreatic Stone Protein)
Pancreatic secretion of mammals contains about 20 principal protein species (Rinderknecht 1986). Most of these secretory proteins are directly implicated in the digestive process. Our laboratory has reported the presence in human pancreas of a protein apparently devoid of enzyme activity (Montalto et al. 1986) and named secretory pancreatic stone protein (PSP-S) because of its immunological identity with the pancreatic stone protein, the major component of the protein matrix present in calculi of patients suffering from chronic calcifying pancreatitis (CCP). In human pancreatic juice collected over an appropriate mixture of protease inhibitors, PSP-S comprised four species with apparent M r between 16 and 20 kDa, named PSP-S2 to PSP-S5 (de Caro et al. 1988). However, immunoprecipitation of in vitro translation products of pancreatic RNAs showed that PSP-S was synthesised as a single polypeptide (Giorgi et al. 1985a). Hence, PSP-S is a protein entity with a molecular weight heterogeneity probably due to postranslational processing. An additional PSP- S form (PSP-S1) appears in pancreatic juice upon activation. PSP-S1 with a M r of 15 kDa derives from PSP-S2-5 by trypsin-like cleavage of an Arg-Ile bond in the NH2-terminal part of the protein (Rouimi et al. 1987).
KeywordsPancreatitis Amylase Chymotrypsin
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- Miyaura C, Chen L, Appel M, (1991) Expression of reg/PSP, a pancreatic exocrine gene: Relationship to changes in islet p-cell mass. Mol Endocrinol (in press)Google Scholar
- Multigner L, de Caro A (1987) Pancreatic stone protein. Kinetic studies on calcium carbonate crystal growth inhibition by human pancreatic stone protein. Digestion 38: 43–44Google Scholar
- Rinderknecht H (1986) Pancreatic secretory enzymes. In: Go VLW, Gardner JD, Brooks FP, Lebenthal E, DiMagno EP, Scheele JA (eds) The exocrine pancreas: biology, pathology and diseases, Raven Press, New York, pp 163–183Google Scholar
- Rouqier S, Verdier JM, Iovanna J, Dagorn JC, Giorgi D (1991) Rat pancreatic stone protein messenger RNA. Abundant expression in mature exocrine cells, regulation by food content, and sequence identity with the endocrine reg transcript. J Biol Chem 266: 786–787Google Scholar
- Stroud RM, Krieger M, Koeppe RE, Kossiakoff AA, Chambers JL (1975) Structure-function relationships in the serine proteases. In: Reich E, Rifkin DB, Shaw E (eds) Proteases and biological control. Cold Spring Harbor Laboratory, New York, pp 13–32Google Scholar
- Watanabe T, Yonekura H, Terazono K, Yamamoto H, Okamoto H (1990) Complete nucleotide sequence of human reg gene and its expression in normal and tumoral tissues. The reg protein, pancreatic stone protein, and pancreatic thread protein are one and the same product of the gene. J Biol Chem 265: 7432–7439PubMedGoogle Scholar