Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.11.18 (MAP)
 7,412 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bioactive peptides with a variety of effects have been described from several nutritive proteins. They exhibit antimicrobial, blood-pressure lowering, antithrombotic, immunomodulatory, and cholesterol-modulating effects. In this study, we have examined whether peptides derived from food proteins might influence bile acid synthesis. A reporter gene cell line that carries a cholesterol 7alpha-hydroxylase promoter fragment fused to firefly luciferase ( cyp7a-luc) was used to screen for nutritive peptides affecting cyp7a expression, the enzyme catalyzing the rate-limiting step in bile acid synthesis. Proteolytic hydrolysates were prepared from soy protein and bovine casein with pepsin, trypsin, chymotrypsin, and elastase and size fractionated using ultrafiltration. Several bioactive hydrolysates could be identified that inhibited luciferase expression. Also, an activation of kinase (AKT, ERK, p38-MAPK) signaling could be observed. Selected hydrolysates were further fractionated by reversed-phase HPLC. Bioactive HPLC-fractions were obtained from casein but not from soy hydrolysates; however, activity could not be recovered in single peak fractions. Peptides in such fractions were identified by mass spectrometry. Five selected peptides from alpha S1-casein present in active fractions were synthesized, but none of these showed activity in the cyp7a-luc screening system. However, two of them activated MAP-kinase signaling similar to the hydrolysates, which suggests, that these peptides are involved in cyp7a regulation by the casein hydrolysates.
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PMID:Screening for nutritive peptides that modify cholesterol 7alpha-hydroxylase expression. 1854 26

This study was designed to investigate the effect of dietary phytate and phytase on proteolytic digestion and growth signalling in the gastrointestinal tract of broilers. Diets containing phytate phosphorus (2.2 or 4.4 g/kg) with phytase dose rates of 0, 500, or 1,000 FTU/kg were fed to 504 female Cobb chicks for three weeks. Diets containing high phytate reduced the activity of pepsin and trypsin, whereas the inclusion of microbial phytase increased the activity of pepsin, H(+)K(+)-ATPase, trypsin and alanyl aminopeptidase. In the intestine, phytate upregulated the mRNA expression of somatostatin, and down-regulated the mRNA expressions of ghrelin and target of rapamycin (TOR). Phytase down regulated the somatostatin gene, and upregulated the genes of ghrelin, TOR, p70 S6 kinase (S6K) and methionyl aminopeptidase. Significant interactions between phytate and phytase on the mRNA expressions of ghrelin, somatostatin and S6K in the jejunum were detected. The results suggest that dietary phytate and phytase can influence the gastrointestinal endocrine and exocrine systems, as well as the peripherally regulatory network of growth in broilers.
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PMID:Effect of dietary phytate and phytase on proteolytic digestion and growth regulation of broilers. 2696 99