Figure 17.13A.3.

N-linked glycan maturation pathway for complex types, and sensitivities to various enzymes (see Fig. 17.13A.2 for additional details). (8) GlcNAc transferase II adds a second GlcNAc to initiate a biantennary chain. (9) GlcNAc transferase IV adds a third GlcNAc to initiate a triantennary chain. (10) GlcNAc transferase V adds a fourth GlcNAc to initiate a tetraantennary chain. (11) Fucosyltransferase adds α1-6Fuc to the core region of complex chains. (12) β1-4Gal is added to available GlcNAc residues of hybrid and complex chains. (13) α2-3 or α2-6Sia is added to Gal residues of hybrid and complex chains. For the color version of the figure go to http://www.currentprotocols.com/protocol/mb1713a.