Incubation of Locust bean gum with an Aspergillus niger beta-D-mannanase released a wide variety of galactomannan oligomers. A single heptasaccharide, digalactosylmannopentaose, was obtained from fractionation of the mixture by size exclusion chromatography. The purity and chemical composition of the sample was demonstrated using mass spectrometry, high performance anion-exchange chromatography and monosaccharide composition analysis. The primary structure of this heptasaccharide was unambiguously identified using 2D 1H and 13C homonuclear and heteronuclear NMR. A complete assignment of the 1H and 13C signals of this oligomer was achieved, producing an NMR dataset that will be of importance in the primary structure elucidation of larger and more complex galactomannan oligomers.
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http://dx.doi.org/10.1016/0008-6215(95)00038-u | DOI Listing |
Comput Struct Biotechnol J
June 2022
Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Makhanda, Eastern Cape 6140, South Africa.
Both β-mannanases and β-mannosidases are required for mannan-backbone degradation into mannose. In this study, two β-mannosidases of glycoside hydrolase (GH) families 2 (BtMan2A) and 5 (CmMan5A) were evaluated for their substrate specificities and galactomannan binding ability. BtMan2A preferred short -oligomers, while CmMan5A preferred longer ones; DP >2, and galactomannans.
View Article and Find Full Text PDFmSphere
January 2020
Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, Kumamoto, Japan
The pathogenic fungus contains galactomannans localized on the surface layer of its cell walls, which are involved in various biological processes. Galactomannans comprise α-(1→2)-/α-(1→6)-mannan and β-(1→5)-/β-(1→6)-galactofuranosyl chains. We previously revealed that GfsA is a β-galactofuranoside β-(1→5)-galactofuranosyltransferase involved in the biosynthesis of β-(1→5)-galactofuranosyl chains.
View Article and Find Full Text PDFBioresour Technol
January 2020
Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands. Electronic address:
α-Galactosidases are important industrial enzymes for hemicellulosic biomass degradation or modification. In this study, six novel extracellular α-galactosidases from Penicillium subrubescens were produced in Pichia pastoris and characterized. All α-galactosidases exhibited high affinity to pNPαGal, and only AglE was not active towards galacto-oligomers.
View Article and Find Full Text PDFBiotechnol Bioeng
July 2014
Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, 1084 Columbia Avenue, Riverside, California, 92507; BioEnergy Science Center (BESC), Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831-6422.
Cellulase enzymes contribute a major fraction of the total cost for biological conversion of lignocellulosic biomass to fuels and chemicals. Although a several fold reduction in cellulase production costs and enhancement of cellulase activity and stability have been reported in recent years, sugar yields are still lower at low enzyme doses than desired commercially. We recently reported that hemicellulose xylan and its oligomers strongly inhibit cellulase and that supplementation of cellulase with xylanase and β-xylosidase would significantly reduce such inhibition.
View Article and Find Full Text PDFCarbohydr Res
November 2011
Mass Spectrometry Centre, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
The hydroxyl radicals are widely implicated in oxidation of carbohydrates during biological and industrial processes being responsible for their structural modifications and causing functional damage. The identification of intermediate oxidation products is hampered by a lack of reliable sensible methods for their detection. In this study, the oxidation of two models of galactomannans (Man(3) and GalMan(2)) has been studied in reaction with hydroxyl radical generated by Fenton reaction.
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