Terminal glycotope expression on milk fibronectin differs from plasma fibronectin and changes over lactation

O-Glycosylation of α-1-Acid Glycoprotein of Human Milk Is Lactation Stage Related

“…11,16,30 In particular, binding of lectins to ELISA plate-isolated glycoproteins and other lectin-based methods allow rapid and exhaustive analysis and are useful for detecting even weak interactions due to multivalent glycotope-lectin interactions. 11,12,29,31 Additionally, the results obtained using lectinbased methods are reported to be well correlated with mass spectrometry analysis of glycan structures. 16 The observed differences in the reactivities of human milk and plasma AGP with the panel of O-glycan specific lectins (Table 1 and Fig.…”

“…Differences in O-glycosylation between serum/plasma and milk were reported for secretory immunoglobulin A 9 and fibronectin. 12 The differences are likely to be due to the different glycosylation enzymes in the plasma cells located in the bone marrow/ spleen/liver from those at different mucosal surfaces. 9 The O-glycan structures and sites of their attachment differ significantly among tissues.…”

“…The positive control for Jacalin, PNA, and VVA was glycophorin, asialo-glycophorin, and asialo-submaxillary mucin, respectively. 12 The negative control was a human albumin preparation (Sigma) included in the test instead of milk and plasma samples. The background absorbance was low (range from 0.03 to 0.06 AU) when Tris-buffered saline was included in the tests instead of (1) lectin, (2) ExtrAvidin-alkaline phosphatase, and (3) milk or plasma samples.…”

“…Over the process of lactation, within milk maturation, the degree and type of sialylation and fucosylation of milk glycoproteins change and partly overlap with observed trends for HMOs abundantly present in milk. 6,11,12 Gao et al 13 have suggested that alteration in glycan structures during lactation goes hand in hand with a transformation in defense mechanisms that occur from newborns to young infants.…”

“…Moreover, as suggested by Newburg, 2 some human milk oligosaccharides (HMOs) may provide a background for construction of innovative therapeutics as well as prophylactic bioagents given for neonates during the postnatal period, particularly those delivered preterm in unfavorable and detrimental conditions. So far the free HMOs, 1 human milk N-glycome, 5 and glycan profiles of N-and/or O-glycans of some glycoproteins, 6 such as lactoferrin, 7 bile salt-stimulated lipase, 8 secretory immunoglobulin A, 9,10 a-1-acid glycoprotein (AGP), 11 and fibronectin, 12 have been characterized in detail. Over the process of lactation, within milk maturation, the degree and type of sialylation and fucosylation of milk glycoproteins change and partly overlap with observed trends for HMOs abundantly present in milk.…”