Identification of two major proteins of bovine pancreatic stones as immunoreactive forms of trypsinogens

Abstract

Two major proteins have been identified in sodium citrate extracts of bovine pancreatic stones from 15 glands with lithiasis. They were found to have a molecular weight of about 24 000 and were further characterized by a variety of methods, including polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate, isoelectric focusing, two-dimensional electrophoresis, immunodiffusion, immunoelectrophoresis and determination of N-terminal residues. These two immunologically and electrophoretically different proteins were definitely shown to be immunoreactive forms of anionic and cationic trypsinogens, which are normal components of pancreatic juice. However, in contrast with both secretory trypsinogens, the stone proteins displayed an important charge heterogeneity under isoelectric-focusing conditions. A possible role for both secretory trypsinogens in pancreatic lithogenesis is suggested by the reproducibility of the data. Finally, two minor proteins with a lower molecular weight (about 11 000-13 000) have also been found to be present in all extracts, but have not yet been identified.

Analysis of the Proteinaceous Components of the Organic Matrix of Calcitic Sclerites from the Soft Coral Sinularia sp.

“…However, SSCL-75 was not identified as a glycoprotein by periodic acid Schiff analysis, suggesting that this protein has a limited function in the biocalcification process. Some other proteins, such as hypothetical and fluorescent, might have functional roles in biocalcification [33], [34], [35], although the putative function of the hypothetical proteins could not be defined.…”

Partial amino acid sequence of human pancreatic stone protein, a novel pancreatic secretory protein

“…However, PSP and PSP-S1 are not identical molecules: no trace of phosphorus could be detected in PSP-S1, and PSP-S1 gives a single band on isoelectric focusing (pI 6.25), whereas PSP gives several bands (pl 5.1, 5.5 and 5.8) (De . These charge differences could be due either to a lack of phosphorus or to a deamidation reaction, which has been observed to result in a shift from negatively to positively charged proteins in bovine pancreatic stones (De Caro et al, 1982). Guy-Crotte et al (1984) have reported the partial characterization ofa protein present in human pancreatic juice, referred to as 'protein X.…”

The molecular characteristics of a human pancreatic acidic phosphoprotein that inhibits calcium carbonate crystal growth

“…The stones were extensively washed in 0.15 M-NaCl under continuous magnetic stirring to remove contaminating superficial proteins. The dried stones were ground in a Dangoumau mill (Prolabo), and the resultant powder was demineralized by repeated extractions in 0.5M-disodium EDTA, pH 8.0 (De Caro et al, 1982). PSP was shown to be pure in only seven out of 61 patients by the use of immunochemical analysis, disc electrophoresis and N-terminal analysis.…”