N-Linked Glycan Profiling of Mature Human Milk by High-Performance Microfluidic Chip Liquid Chromatography Time-of-Flight Tandem Mass Spectrometry

• Published in: Journal of agricultural and food chemistry Vol. 59; no. 8; pp. 4255 - 4263
• Main Authors: Dallas, David C, Martin, William F, Strum, John S, Zivkovic, Angela M, Smilowitz, Jennifer T, Underwood, Mark A, Affolter, Michael, Lebrilla, Carlito B, German, J. Bruce
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 27.04.2011
• Subjects: adhesion; Biological and medical sciences; breast milk; carbon; cell growth; Chromatography, High Pressure Liquid - methods; Food industries; Fundamental and applied biological sciences. Psychology; human milk proteins; Humans; liquid chromatography; mass spectrometry; Mass Spectrometry - methods; Microfluidics - methods; milk; Milk, Human - chemistry; Molecular Nutrition; Mother. Fetoplacental unit. Mammary gland. Milk; mothers; polysaccharides; Polysaccharides - chemistry; Pregnancy. Parturition. Lactation; Vertebrates: reproduction; glycoproteomics; oligosaccharide; LC-MS; glycomics; sialic acid; time-of-flight mass spectrometry; prebiotics; human milk; glycoprotein; glycobiology; N-linked glycan; Sialic acid; Oligosaccharide; Glycoprotein; HPLC chromatography; Liquid chromatography; Glycan; Prebiotics; Human milk; Mass spectrometry
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf104681p

N-Linked glycans of skim human milk proteins were determined for three mothers. N-Linked glycans are linked to immune defense, cell growth, and cell−cell adhesion, but their functions in human milk are undetermined. Protein-bound N-linked glycans were released with peptidyl N-glycosidase F (PNGase F), enriched by graphitized carbon chromatography, and analyzed with Chip-TOF MS. To be defined as N-glycans, compounds were required, in all three procedural replicates, to match, within 6 ppm, against a theoretical human N-glycan library and be at least 2-fold higher in abundance in PNGase F-treated than in control samples. Fifty-two N-linked glycan compositions were identified, and 24 were confirmed via tandem mass spectra analysis. Twenty-seven compositions have been found previously in human milk, and 25 are novel compositions. By abundance, 84% of N-glycans were fucosylated and 47% were sialylated. The majority (70%) of total N-glycan abundance was composed of N-glycans found in all three milk samples.