Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Degradations by proteolytic enzymes and intestinal epithelial permeability represent two major drawbacks to the transfer of food protein antigens to blood. These steps were studied in vitro for the milk protein antigens beta-lactoglobulin (beta-Lg), alpha-Lactalbumin (alpha-La) and beta-casein (beta-cas). Pepsin-trypsin hydrolysis and permeability in isolated rabbit ileum in Ussing chamber were suited by ELISA and radiolabelled-protein measurement. Pepsin-trypsin hydrolysis showed an increasing resistance in the order beta-cas less than alpha-La less than beta-Lg. The rate of absorption of the antigenic proteins by isolated rabbit ileum was in the same order, and the rate of absorption of the whole proteins (degraded and antigenic forms) was significantly higher for beta-Lg than for alpha-La and beta-cas. These results suggest a selective intestinal permeability for milk protein antigens. This selectivity is probably important in the mechanism of food protein sensitization via the oral route.
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PMID:Permeability of milk protein antigens across the intestinal epithelium in vitro. 262 77

Conditions for the release of beta-casomorphin-7 from bovine beta-casein by gastrointestinal proteases in vitro were investigated. beta-Casomorphin-7 was released only from a genetic variant of beta-casein containing a His residue at the 67th position of the peptide chain. Elastase cleaved the peptide bond between Ile66 and His67, releasing the carboxyl terminus of beta-casomorphin-7. Pepsin and leucine aminopeptidase were required to release the amino terminus of this peptide. beta-Casomorphin-9, -13, and -21 also were isolated, and their opioid activities were measured. In this study, we also isolated a novel opioid peptide neocasomorphin-6 (Tyr-Pro-Val-Glu-Pro-Phe), which was released by action of trypsin or pepsin and chymotrypsin.
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PMID:Enzymatic release of neocasomorphin and beta-casomorphin from bovine beta-casein. 1050 74