Comprehensive Analysis of the Glycome and Glycoproteome of Bovine Milk-Derived Exosomes

Bovine milk-derived exosomes (BMDEs)
have potential applications
in the pharmaceutical industry as drug delivery carriers. A comprehensive
analysis of protein glycosylation in exosomes is necessary to elucidate
the process of targeted delivery. In this work, free oligosaccharides
(FOSs), O-glycans, and N-glycans
in BMDEs and whey were first analyzed through multiple derivation
strategies. In summary, 13 FOSs, 44 O-glycans, and
94 N-glycans were identified in bovine milk. To analyze
site-specific glycosylation of glycoproteins, a one-step method was
used to enrich and characterize intact glycopeptides. A total of 1359
proteins including 114 glycoproteins were identified and most of these
were located in the exosomes. Approximately 95 glycopeptides were
initially discovered and 5 predicted glycosites were confirmed in
BMDEs. Collectively, these findings revealed the characterization
and distribution of glycans and glycoproteins in BMDEs, providing
insight into the potential applications of BMDEs in drug delivery
and food science.