Structural Analysis of Laminarin-Derived Oligosaccharides Produced by Transglycosylation of Exo-β-1,3-glucanase ScEXG1 from Saccharomyces cerevisiae
Journal
Journal of Agricultural and Food Chemistry
Journal Volume
74
Journal Issue
1
Start Page
1053
End Page
1062
ISSN
0021-8561
Date Issued
2025-12-24
Author(s)
Abstract
Exo-β-1,3-glucanase EXG1 (ScEXG1) from Saccharomyces cerevisiae hydrolyzes β-1,3-glucans and exhibits transglycosylation activity, enabling biocatalytic synthesis of prebiotic oligosaccharides. In this study, recombinant ScEXG1–6 × His was tested with laminaribiose as both the donor and acceptor. Under low-enzyme dosage, transglycosylation products were detected across a range of substrate concentrations (4.38–32.85 mM), with 21.9 mM laminaribiose producing 270.70 ± 10.32 nmol/mL of the main trisaccharide product-DP3 (DP3) after 3 h. Structural elucidation by HPLC-ESI-MS/MS identified DP3 as β-Glc-(1→6)-β-Glc-(1→3)-Glc based on glycosidic and cross-ring fragmentation patterns. Two additional tetrasaccharides were also characterized as β-Glc-(1→3)-β-Glc-(1→6)-β-Glc-(1→3)-Glc (DP4–1) and β-Glc-(1→6)-β-Glc-(1→3)-β-Glc-(1→3)-Glc (DP4–2). The findings highlight ScEXG1’s ability to produce structurally diverse β-glucan oligosaccharides under mild conditions, thereby expanding enzymatic strategies for prebiotic oligosaccharide production.
Subjects
glycosyl hydrolases (GHs)
laminarin-derived oligosaccharides
Saccharomyces cerevisiaeEXG1 (ScEXG1)
structural characterization
transglycosylation
Publisher
American Chemical Society (ACS)
Type
journal article