Journal article

Publication year: 2008

Pages: 4987-4994

Journal: Journal of Agricultural and Food Chemistry

Volume number: 56

Issue number: 13

ISSN: 0021-8561

DOI Link: https://doi.org/10.1021/jf072806p

Publisher: American Chemical Society

Abstract: 
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 7 alpha-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 HPI-C-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.

Harvard Citation style: Nass, N., Schöps, R., Ulbrich-Hofmann, R., Simm, A., Hohndorf, L., Schmelzer, C., et al. (2008) Screening for Nutritive Peptides That Modify Cholesterol 7α-Hydroxylase Expression, Journal of Agricultural and Food Chemistry, 56(13), pp. 4987-4994. https://doi.org/10.1021/jf072806p

APA Citation style: Nass, N., Schöps, R., Ulbrich-Hofmann, R., Simm, A., Hohndorf, L., Schmelzer, C., Raith, K., Neubert, R., & Eder, K. (2008). Screening for Nutritive Peptides That Modify Cholesterol 7α-Hydroxylase Expression. Journal of Agricultural and Food Chemistry. 56(13), 4987-4994. https://doi.org/10.1021/jf072806p