Figure 17-30. Structures of typical O-linked and N-linked oligosaccharides.

Figure 17-30Structures of typical O-linked and N-linked oligosaccharides

(a) The O-linked oligosaccharides in glycophorin and many other glycoproteins are linked to the hydroxyl group in serine (Ser) and threonine residues by N-acetylgalactosamine. Collagens contain a characteristic glucose → galactose di-saccharide attached to hydroxylysine (Hyl) residues. (b) TheN-linked oligosaccharides found in mammalian serum glycoproteins exhibit various structures, but all contain the five sugars highlighted in purple, are branched, and are linked to the amide nitrogen of asparagine (Asn). [After R. Kornfeld and S. Kornfeld, 1985, Annu. Rev. Biochem. 45:631.]

From: Section 17.7, Protein Glycosylation in the ER and Golgi Complex

Cover of Molecular Cell Biology
Molecular Cell Biology. 4th edition.
Lodish H, Berk A, Zipursky SL, et al.
New York: W. H. Freeman; 2000.
Copyright © 2000, W. H. Freeman and Company.

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