Β-Galactosidase from Ginkgo biloba seeds active against β-galactose-containing N-glycans: purification and characterization. Issue 9 (2nd September 2015)

• Record Type: Journal Article
• Authors: Rahman, Md Ziaur; Maeda, Megumi; Kimura, Yoshinobu
• Is Part Of: Bioscience, biotechnology, and biochemistry. Volume 79:Issue 9(2015)
• Page Start: 1464
• Page End: 1472
• Publication Date: 2015-09-02
• Subjects: β-galactosidase -- plant N-glycan -- N-glycan degradation -- glycosidase -- Ginkgo biloba; Biotechnology -- Periodicals; Biochemistry -- Periodicals; 660.6
• DOI: 10.1080/09168451.2015.1034653
• Languages: English
• ISSNs: 0916-8451

Abstract

Abstract: In this study, we purified an acidic β-galactosidase to homogeneity from Ginkgo biloba seeds (β-Gal'ase Gb-1) with approximately 270-fold purification. A molecular mass of the purified β-Gal'ase Gb-1 was estimated about 35 kDa by gel filtration and 32 kDa by SDS-PAGE under non-reducing condition, respectively. On the other hand, β-Gal'ase Gb-1 produced a single band with a molecular mass of 16 kDa by SDS-PAGE under reducing condition. The N -terminal amino acid sequences of 32 kDa and 16 kDa molecules were the same and identified as H-K-A-N-X-V-T-V-A-F-V-M-T-Q-H-, suggesting that β-Gal'ase Gb-1 may function as a homodimeric structure in vivo . When complex-type N -glycans containing β-galactosyl residues were used as substrates, β-Gal'ase Gb-1 showed substantial activity for β1-4 galactosyl residue and modest activity for β1-3 galactosyl residue with an optimum pH near 5.0. Based on these results, the involvement of β-Gal'ase Gb-1 in the degradation of plant complex-type N -glycans is discussed. Graphical abstract: : Low-molecular-weight β-galactosidase from Ginkgo biloba seeds (β-Gal'ase Gb) release β-galactosyl residues from both animal complex type and plant complex N -glycans.