Identification and comparison of N-glycome profiles from common dietary protein sources

The N-glycomes of bovine whey, egg white, pea, and soy protein isolates are described here. N-glycans from four protein isolates were analyzed by HILIC high performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry (HILIC-FLD-QTOF-MS/MS). In total, 33 N-glycans from bovine whey and egg white and 10 N-glycans from soy and pea glycoproteins were identified. The type of N-glycans per glycoprotein source were attributable to differences in biosynthetic glycosylation pathways. Animal glycoprotein sources favored a combination of complex and hybrid glycan configurations, while the plant proteins were dominated by oligomannosidic N-glycans. Bovine whey glycoprotein isolate contained the most diverse N-glycans by monosaccharide composition as well as structure, while plant sources such as pea and soy glycoprotein isolates contained an overlap of oligomannosidic N-glycans. The results suggest N-glycan structure and composition is dependent on the host organism which are driven by the differences in N-glycan biosynthetic pathways.