A Novel α1,2-l-Fucosidase Acting on Xyloglucan Oligosaccharides is Associated with Endo-β-Mannosidase*.

Ishimizu, Takeshi; Hashimoto, Chikako; Takeda, Ryo; Fujii, Kenta; Hase, Sumihiro

Endo-β-mannosidase, which hydrolyses the Manβ1-4GlcNAc linkage of N-glycans in an endo-manner, was discovered in plants. During the course of the purification of the enzyme from lily flowers, we found a higher molecular mass form of the enzyme (designated as EBM II). EBM II was purified by column chromatography to homogeneity and its molecular composition revealed EBM II to be comprised of endo-β-mannosidase and an associated protein. The cDNA of this associated protein encodes a protein with slight homology to the fucosidase domain of bifidus AfcA. EBM II has α1,2-l-fucosidase activity and acts on a fucosylated xyloglucan nonasaccharide. The amino acid sequence of this associated protein has no similarity to known plant α-l-fucosidases. These results show that EBM II is a novel α1,2-l-fucosidase and a protein complex containing endo-β-mannosidase.

GLUCANS; OLIGOSACCHARIDES; PROTEINS; PLANT enzymes; AMINO acid sequence

Journal of Biochemistry, 2007, Vol 142, Issue 6, p721

0021-924X

Academic Journal

10.1093/jb/mvm186