Figure 3.

Biosynthesis pathway of complex type N-glycans. The reactions of α1,6-FucT, GnT-IV and GnT-V and complex type N-glycan structures in this study are highlighted. GnT-IV and GnT-V increase number of antenna, and some of them are modified by α1,6-FucT. Then, they are galactosylated by β1,4- galactosyltransferase as shown as black arrows. The products of GnT-V were modified by GnT-IV in this study, so we have indicated that GnT-V works after GnT-IV in the biosynthetic pathway. However, it is possible that GnT-V may act at an earlier step than GnT-IV.