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|Stability:||> 10 years under recommended storage conditions|
|Monosaccharides (%):||Mannose: Galactose: Other sugars = 98: 1: 1|
|Main Chain Glycosidic Linkage:||β-1,4|
|Substrate For (Enzyme):||endo-1,4-β-Mannanase|
High purity Mannan (1,4-β-D-Mannan) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
Prepared by controlled hydrolysis of carob galactomannan with β-mannanase and α-galactosidase. An excellent substrate for endo-1,4-β-D-mannanase.
Engineering of β-mannanase from Aspergillus niger to increase product selectivity towards medium chain length mannooligosaccharides.
Arunrattanamook, N., Wansuksri, R., Uengwetwanit, T. & Champreda, V. (2020). Journal of Bioscience and Bioengineering, In Press.
Mannooligosaccharides (MOSs) are one of the most commonly used biomass-derived feed additives. The effectiveness of MOS varies with the length of oligosaccharides, medium length MOSs such as mannotetraose and mannopentaose being the most efficient. This study aims at improving specificity of β-mannanase from Aspergillus niger toward the desirable product size through rational-based enzyme engineering. Tyr 42 and Tyr 132 were mutated to Gly to extend the substrate binding site, allowing higher molecular weight MOS to non-catalytically bind to the enzyme. Hydrolysis product content was analyzed by high-performance anion-exchange chromatography with pulsed amperometric detection. Instead of mannobiose, the enzyme variants yielded mannotriose and mannotetraose as the major products, followed by mannobiose and mannopentaose. Overall, 42% improvement in production yield of highly active mannotetraose and mannopentaose was achieved. This validates the use of engineered β-mannanase to selectively produce larger MOS, making them promising candidates for large-scale MOS enzymatic production process.Hide Abstract
Identification of a unique 1, 4-β-d-glucan glucohydrolase of glycoside hydrolase family 9 from Cytophaga hutchinsonii.
Jiang, N., Ma, X. D., Fu, L. H., Li, C. X., Feng, J. X. & Duan, C. J. (2020). Applied Microbiology and Biotechnology, 1-16.
Cytophaga hutchinsonii is an aerobic cellulolytic soil bacterium that rapidly digests crystalline cellulose. The predicted mechanism by which C. hutchinsonii digests cellulose differs from that of other known cellulolytic bacteria and fungi. The genome of C. hutchinsonii contains 22 glycoside hydrolase (GH) genes, which may be involved in cellulose degradation. One predicted GH with uncertain specificity, CHU_0961, is a modular enzyme with several modules. In this study, phylogenetic tree of the catalytic modules of the GH9 enzymes showed that CHU_0961 and its homologues formed a new group (group C) of GH9 enzymes. The catalytic module of CHU_0961 (CHU_0961B) was identified as a 1,4-β-D-glucan glucohydrolase (EC 18.104.22.168) that has unique properties compared with known GH9 cellulases. CHU_0961B showed highest activity against barley glucan, but low activity against other polysaccharides. Interestingly, CHU_0961B showed similar activity against ρ-nitrophenyl β-D-cellobioside (ρ-NPC) and ρ-nitrophenyl β-D-glucopyranoside. CHU_0961B released glucose from the nonreducing end of cello-oligosaccharides, ρ-NPC, and barley glucan in a nonprocessive exo-type mode. CHU_0961B also showed same hydrolysis mode against deacetyl-chitooligosaccharides as against cello-oligosaccharides. The kcat/Km values for CHU_0961B against cello-oligosaccharides increased as the degree of polymerization increased, and its kcat/Km for cellohexose was 750 times higher than that for cellobiose. Site-directed mutagenesis showed that threonine 321 in CHU_0961 played a role in hydrolyzing cellobiose to glucose. CHU_0961 may act synergistically with other cellulases to convert cellulose to glucose on the bacterial cell surface. The end product, glucose, may initiate cellulose degradation to provide nutrients for bacterial proliferation in the early stage of C. hutchinsonii growth.Hide Abstract
Hsu, Y., Koizumi, H., Otagiri, M., Moriya, S. & Arioka, M. (2018). Applied Microbiology and Biotechnology, 1-11.
Symbiotic protists in the hindgut of termites provide a novel enzymatic resource for efficient lignocellulytic degradation of plant biomass. In this study, two β-mannanases, RsMan26A and RsMan26B, from a symbiotic protist community of the lower termite, Reticulitermes speratus, were successfully expressed in the methylotrophic yeast, Pichia pastoris. Biochemical characterization experiments demonstrated that both RsMan26A and RsMan26B are endo-acting enzymes and have a very similar substrate specificity, displaying a higher catalytic efficiency to galactomannan from locust bean gum (LBG) and glucomannan than to β-1,4-mannan and highly substituted galactomannan from guar gum. Homology modeling of RsMan26A and RsMan26B revealed that each enzyme displays a long open cleft harboring a unique hydrophobic platform (Trp79) that stacks against the sugar ring at subsite - 5. The Km) values of W79A mutants of RsMan26A and RsMan26B to LBG increased by 4.8-fold and 3.6-fold, respectively, compared with those for the native enzymes, while the kcat) remained unchanged or about 40% of that of the native enzyme, resulting in the decrease in the catalytic efficiency by 4.8-fold and 9.1-fold, respectively. The kinetic values for glucomannan also showed a similar result. These results demonstrate that the Trp residue present near the subsite - 5 has an important role in the recognition of the sugar ring in the substrate.Hide Abstract
Liu, B., Olson, Å., Wu, M., Broberg, A. & Sandgren, M. (2017). PloS One, 12(12), e0189479.
Lytic polysaccharide monooxygenases (LPMO) are important redox enzymes produced by microorganisms for the degradation of recalcitrant natural polysaccharides. Heterobasidion irregulare is a white-rot phytopathogenic fungus that causes wood decay in conifers. The genome of this fungus encodes 10 putative Auxiliary Activity family 9 (AA9) LPMOs. We describe the first biochemical characterization of H. irregulare LPMOs through heterologous expression of two CBM-containing LPMOs from this fungus (HiLPMO9H, HiLPMO9I) in Pichia pastoris. The oxidization preferences and substrate specificities of these two enzymes were determined. The two LPMOs were shown to cleave different carbohydrate components of plant cell walls. HiLPMO9H was active on cellulose and oxidized the substrate at the C1 carbon of the pyranose ring at β-1,4-glycosidic linkages, whereas HiLPMO9I cleaved cellulose with strict oxidization at the C4 carbon of glucose unit at internal bonds, and also showed activity against glucomannan. We propose that the two LPMOs play different roles in the plant-cell-wall degrading system of H. irregulare for degradation of softwood and that the lignocellulose degradation mediated by this white-rot fungus may require collective efforts from multi-types of LPMOs.Hide Abstract
Cheng, L., Duan, S., Feng, X., Zheng, K., Yang, Q. & Liu, Z. (2016). BioMed Research International, 2016, In Press.
β-mannanase has shown compelling biological functions because of its regulatory roles in metabolism, inflammation, and oxidation. This study separated and purified the β-mannanase from Bacillus subtilis BE-91, which is a powerful hemicellulose-degrading bacterium using a “two-step” method comprising ultrafiltration and gel chromatography. The purified β-mannanase (about 28.2 kDa) showed high specific activity (79, 859.2 IU/mg). The optimum temperature and pH were 65°C and 6.0, respectively. Moreover, the enzyme was highly stable at temperatures up to 70°C and pH 4.5-7.0. The β-mannanase activity was significantly enhanced in the presence of Mn2+, Cu2+, Zn2+, Ca2+, Mg2+, and Al3+, and strongly inhibited by Ba2+, and Pb2+. Km and Vmax values for locust bean gum were 7.14 mg/mL and 107.5 µmol/min/mL versus 1.749 mg/mL and 33.45 µ mol/min/mL for Konjac glucomannan, respectively. Therefore, β-mannanase purified by this work shows stability at high temperatures and in weakly acidic or neutral environments. Based on such data, the β-mannanase will have potential applications as a dietary supplement in treatment of inflammatory processes.Hide Abstract
González-Calle, V., Barrero-Sicilia, C., Carbonero, P. & Iglesias-Fernández, R. (2015). Journal of Experimental Botany, 66(13), 3753-3764.
Immunolocalization of mannans in the seeds of Brachypodium distachyon reveals the presence of these polysaccharides in the root embryo and in the coleorhiza in the early stages of germination (12h), decreasing thereafter to the point of being hardly detected at 27h. Concurrently, the activity of endo-β-mannanases (MANs; EC 22.214.171.124) that catalyse the hydrolysis of β-1,4 bonds in mannan polymers, increases as germination progresses. The MAN gene family is represented by six members in the Brachypodium genome, and their expression has been explored in different organs and especially in germinating seeds. Transcripts of BdMAN2, BdMAN4 and BdMAN6 accumulate in embryos, with a maximum at 24–30h, and are detected in the coleorhiza and in the root by in situ hybridization analyses, before root protrusion (germination sensu stricto). BdMAN4 is not only present in the embryo root and coleorhiza, but is abundant in the de-embryonated (endosperm) imbibed seeds, while BdMAN2 and BdMAN6 are faintly expressed in endosperm during post-germination (36–42h). BdMAN4 and BdMAN6 transcripts are detected in the aleurone layer. These data indicate that BdMAN2, BdMAN4 and BdMAN6 are important for germination sensu stricto and that BdMAN4 and BdMAN6 may also influence reserve mobilization. Whether the coleorhiza in monocots and the micropylar endosperm in eudicots have similar functions, is discussed.Hide Abstract
Wegmann, U., Louis, P., Goesmann, A., Henrissat, B., Duncan, S. H. & Flint, H. J. (2014). Environmental Microbiology, 16(9), 2879–2890.
The recently isolated bacterial strain 80/3 represents one of the most abundant 16S rRNA phylotypes detected in the healthy human large intestine and belongs to the Ruminococcaceae family of Firmicutes. The completed genome sequence reported here is the first for a member of this important family of bacteria from the human colon. The genome comprises two large chromosomes of 2.24 and 0.73 Mbp, leading us to propose the name Ruminococcus bicirculans for this new species. Analysis of the carbohydrate active enzyme complement suggests an ability to utilize certain hemicelluloses, especially β-glucans and xyloglucan, for growth that was confirmed experimentally. The enzymatic machinery enabling the degradation of cellulose and xylan by related cellulolytic ruminococci is however lacking in this species. While the genome indicated the capacity to synthesize purines, pyrimidines and all 20 amino acids, only genes for the synthesis of nicotinate, NAD+, NADP+ and coenzyme A were detected among the essential vitamins and co-factors, resulting in multiple growth requirements. In vivo, these growth factors must be supplied from the diet, host or other gut microorganisms. Other features of ecological interest include two type IV pilins, multiple extracytoplasmic function-sigma factors, a urease and a bile salt hydrolase.Hide Abstract
Ladevèze, S., Tarquis, L., Cecchini, D. A., Bercovici, J., André, I., Topham, C. M., Morel, S., Laville, E., Monsan, P., Lombard, V., Henrissat, B. & Potocki-Véronèse, G. (2013). Journal of Biological Chemistry, 288(45), 32370-32383.
To metabolize both dietary fiber constituent carbohydrates and host glycans lining the intestinal epithelium, gut bacteria produce a wide range of carbohydrate-active enzymes, of which glycoside hydrolases are the main components. In this study, we describe the ability of phosphorylases to participate in the breakdown of human N-glycans, from an analysis of the substrate specificity of UhgbMP, a mannoside phosphorylase of the GH130 protein family discovered by functional metagenomics. UhgbMP is found to phosphorolyze β-D-Manp-1,4-β-D-GlcpNAc-1,4-D-GlcpNAc and is also a highly efficient enzyme to catalyze the synthesis of this precious N-glycan core oligosaccharide by reverse phosphorolysis. Analysis of sequence conservation within family GH130, mapped on a three-dimensional model of UhgbMP and supported by site-directed mutagenesis results, revealed two GH130 subfamilies and allowed the identification of key residues responsible for catalysis and substrate specificity. The analysis of the genomic context of 65 known GH130 sequences belonging to human gut bacteria indicates that the enzymes of the GH130_1 subfamily would be involved in mannan catabolism, whereas the enzymes belonging to the GH130_2 subfamily would rather work in synergy with glycoside hydrolases of the GH92 and GH18 families in the breakdown of N-glycans. The use of GH130 inhibitors as therapeutic agents or functional foods could thus be considered as an innovative strategy to inhibit N-glycan degradation, with the ultimate goal of protecting, or restoring, the epithelial barrier.Hide Abstract
Park, Y. B. & Cosgrove, D. J. (2012). Plant Physiology, 158(4), 1933-1943.
Xyloglucan is widely believed to function as a tether between cellulose microfibrils in the primary cell wall, limiting cell enlargement by restricting the ability of microfibrils to separate laterally. To test the biomechanical predictions of this “tethered network” model, we assessed the ability of cucumber (Cucumis sativus) hypocotyl walls to undergo creep (long-term, irreversible extension) in response to three family-12 endo-β-1,4-glucanases that can specifically hydrolyze xyloglucan, cellulose, or both. Xyloglucan-specific endoglucanase (XEG from Aspergillus aculeatus) failed to induce cell wall creep, whereas an endoglucanase that hydrolyzes both xyloglucan and cellulose (Cel12A from Hypocrea jecorina) induced a high creep rate. A cellulose-specific endoglucanase (CEG from Aspergillus niger) did not cause cell wall creep, either by itself or in combination with XEG. Tests with additional enzymes, including a family-5 endoglucanase, confirmed the conclusion that to cause creep, endoglucanases must cut both xyloglucan and cellulose. Similar results were obtained with measurements of elastic and plastic compliance. Both XEG and Cel12A hydrolyzed xyloglucan in intact walls, but Cel12A could hydrolyze a minor xyloglucan compartment recalcitrant to XEG digestion. Xyloglucan involvement in these enzyme responses was confirmed by experiments with Arabidopsis (Arabidopsis thaliana) hypocotyls, where Cel12A induced creep in wild-type but not in xyloglucan-deficient (xxt1/xxt2) walls. Our results are incompatible with the common depiction of xyloglucan as a load-bearing tether spanning the 20- to 40-nm spacing between cellulose microfibrils, but they do implicate a minor xyloglucan component in wall mechanics. The structurally important xyloglucan may be located in limited regions of tight contact between microfibrils.Hide Abstract