Abstract
The question whether and which non-human peptides or proteins are present in human milk was raised many decades ago. However, due to cross-reactivity or nonspecific antibody recognition, the accuracy of detection by immunochemical methods has been a concern. Additionally, the relative low-abundance of non-human peptides/proteins in the complex milk sample makes them a challenging target to detect. Here, by deep proteome profiling we detected several non-human peptides, which could be grouped as non-human proteins. We next estimated their concentration in human milk by combining data-dependent shotgun proteomics and parallel reaction monitoring. First, we fractionated human milk at the protein level and were able to detect 1577 human proteins. Additionally, we identified 109 non-human peptides, of which 71 were grouped in to 36 non-human proteins. In the next step, we targeted 37 non-human peptides and 9 of them could be repeatedly quantified in human milk samples. Peptides/proteins originating from bovine milk products were the dominant non-human proteins observed, notably bovine caseins (α-S1-, α-S2-, β-, κ-caseins) and β-lactoglobulin. The method we present here can be expanded to investigate more about non-human peptides and proteins in human milk and have a better understanding of how human milk plays a role in allergy prevention.
Original language | English |
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Pages (from-to) | 225-238 |
Number of pages | 14 |
Journal | Journal of Proteome Research |
Volume | 18 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2019 |
Keywords
- nonhuman peptides
- nonhuman proteins
- shotgun proteomics
- parallel reaction monitoring
- mass spectrometry
- human milk