Oligosaccharide galactose

Figure 2.17 Production of oligosaccharides during the hydrolysis of lactose by /5-galactosidase . lactose , monosaccharides O, glucose , oligosaccharides , galactose (modified from Mahoney, 1997).

Transformation of the raw spectrum from the heavy-chain component shows the presence of three species with molecular weights of 50517.2, 50676.8 and 50 840.2 Da, which were rationalized in terms of the oligosaccharide structures shown in Figure 5.9 - the differences of 162 Da corresponding to a dehydrated galactose residue (CeH Oe - H2O). 

Arabinose, fructose, galactose, glucose, maltose, mannose, mucilages of various compositions, oligosaccharides, raffinose, rhamnosc, ribose, sucrose, xylose Amino acids... 

Fig. 8. Different products with sucrose analogues as substrates.115 Enzymatic synthesis of 1-kestose, 1-nystose, and their analogues by /(-fructofuranosidase of A. niger. Structures of fructo-oligosaccharides (A) commercial products, (B) mannose- (C) galactose-, and (D) xylose-substituted analogues.

Figure 2.10 Structure of two sample oligosaccharide side chains (one N-linked the other O-linked) found in glycoproteins. Man manose Gal galactose SA sailic acid GlcNAc W-acetyl glucosamine GalNAc W-acetyl galactosamine...

Incomplete (N-linked) glycosylation prompts decreased in vivo activity due to more rapid hepatic clearance of the EPO molecule. Enzymatic removal of terminal sialic acid sugar residues from oligosaccharides exposes otherwise hidden galactose residues. These residues are then free to bind specific hepatic lectins, which promote EPO removal from the plasma. The reported plasma tm value for native EPO is 4-6 h. The tm for desialated EPO is 2 min. Comparison of native human EPO with its recombinant form produced in CHO cells reveals very similar glycosylation patterns. 

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