Esben Skipper Sørensen

Milk osteopontin retains integrin-binding activity after in vitro gastrointestinal transit

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

DOI

  • B Christensen
  • N J Karlsen
  • ,
  • S D S Jørgensen, Copenhagen Centre for Regulatory Science (CORS), Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark.
  • ,
  • L N Jacobsen, Arla Foods Ingredients Group P/S, DK-8260 Viby J, Denmark.
  • ,
  • M S Ostenfeld, Arla Foods Ingredients Group P/S, DK-8260 Viby J, Denmark.
  • ,
  • S V Petersen
  • A Müllertz, Copenhagen Centre for Regulatory Science (CORS), Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark.
  • ,
  • E S Sørensen

Osteopontin (OPN) is a multifunctional protein highly expressed in milk, where it is hypothesized to be involved in immunological signaling via the conserved Arg-Gly-Asp (RGD) integrin-binding sequence. Intervention studies have indicated beneficial effects of orally administered OPN in animal and human infants, but the mechanisms underlying these effects are not well described. To induce physiological effects, OPN must resist gastrointestinal transit in a bioactive form. In this study, we subjected bovine milk OPN to in vitro gastrointestinal transit, and characterized the generated fragments using monoclonal antibody and mass spectrometric analyses. We found that the fragment Trp27-Phe151 containing the integrin-binding RGD sequence resisted in vitro gastric digestion. This resistance was dependent on glycosylation of threonine residues near the integrin-binding sequence in both human and bovine milk OPN. Furthermore, the fragment Trp27-Phe151 retained the ability to interact with integrins in an RGD-dependent process. These results suggest a mechanism for how ingested milk OPN can induce physiological effects via integrin signaling in the intestine.

Original languageEnglish
JournalJournal of Dairy Science
Volume103
Issue1
Pages (from-to)42-51
Number of pages10
ISSN0022-0302
DOIs
Publication statusPublished - Jan 2020

    Research areas

  • bioactive milk proteins, gastrointestinal digestion, infant formula, osteopontin

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