Steen Vang Petersen

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


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
Pages (from-to)42-51
Number of pages10
Publication statusPublished - Jan 2020

    Research areas

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

See relations at Aarhus University Citationformats

ID: 172527004