Ginkgo biloba α-fucosidase with activity towards plant complex type N-glycans containing the Lewis a epitope: Purification and characterization

　We have identified, and purified to homogeneity, a high molecular weight Ginkgo biloba α-fucosidase (α-fucosidase Gb, 120 kDa estimated by SDS‒PAGE) with activity against α-fucosylated oligosaccharides. When a Lewis a epitope-containing N-glycan was used as a substrate, α-fucosidase Gb showed optimum activity at approximately pH 5.5, suggesting that it functions in acidic environments such as the vacuole. It remains uncertain, however, whether this Ginkgo α-fucosidase belongs to the GH29 family, since its N-terminal sequence could not be determined, probably due to a chemical modification. α-Fucosidase Gb showed substantial activity towards the α1,3-fucosyl linkage in Lacto-N-fucopentaose III and an α1,4-fucosyl linkage in the Lewis a epitope found in plant complex type N-glycans, indicating an involvement in the degradation process of α-fucosylated oligosaccharides or N-glycoproteins.

原著論文 (Original paper)