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BMC Research Notes Jun 2024New characterized carbohydrate-active enzymes are needed for use as tools to discriminate complex carbohydrate structural features. Fungal glycoside hydrolase family 3...
OBJECTIVE
New characterized carbohydrate-active enzymes are needed for use as tools to discriminate complex carbohydrate structural features. Fungal glycoside hydrolase family 3 (GH3) β-xylosidases have been shown to be useful for the structural elucidation of glucuronic acid (GlcA) and arabinofuranose (Araf) substituted oligoxylosides. A homolog of these GH3 fungal enzymes from the bacterium Segatella baroniae (basonym Prevotella bryantii), Xyl3C, has been previously characterized, but those studies did not address important functional specificity features. In an interest to utilize this enzyme for laboratory methods intended to discriminate the structure of the non-reducing terminus of substituted xylooligosaccharides, we have further characterized this GH3 xylosidase.
RESULTS
In addition to verification of basic functional characteristics of this xylosidase we have determined its mode of action as it relates to non-reducing end xylose release from GlcA and Araf substituted oligoxylosides. Xyl3C cleaves xylose from the non-reducing terminus of β-1,4-xylan until occurrence of a penultimate substituted xylose. If this substitution is O2 linked, then Xyl3C removes the non-reducing xylose to leave the substituted xylose as the new non-reducing terminus. However, if the substitution is O3 linked, Xyl3C does not hydrolyze, thus leaving the substitution one-xylose (penultimate) from the non-reducing terminus. Hence, Xyl3C enables discrimination between O2 and O3 linked substitutions on the xylose penultimate to the non-reducing end. These findings are contrasted using a homologous enzyme also from S. baroniae, Xyl3B, which is found to yield a penultimate substituted nonreducing terminus regardless of which GlcA or Araf substitution exists.
Topics: Xylosidases; Xylans; Xylose; Substrate Specificity; Prevotella; Oligosaccharides; Glucuronates; Arabinose
PubMed: 38915023
DOI: 10.1186/s13104-024-06835-3 -
ACS Omega Jun 2024Mushroom polysaccharides are important bioactive compounds derived from mushrooms with various beneficial properties. In this study, the chemical characterization and...
Mushroom polysaccharides are important bioactive compounds derived from mushrooms with various beneficial properties. In this study, the chemical characterization and bioactivities of polysaccharide extracts from four different edible mushrooms, Donk, (Fr.) Quél., (Fr.) Fr., and (Scop.) Singer were studied. Glucose (13.24-56.02%), galactose (14.18-64.05%), mannose (2.18-18.13%), fucose (1.21-5.78%), and arabinose (0.04-5.43%) were identified in all polysaccharide extracts by GC-MS (gas chromatography-mass spectrometry). FT-IR (Fourier transform infrared spectroscopy) confirmed the presence of characteristic carbohydrate patterns. H NMR suggested that all polysaccharide extracts had α- and β-d-mannopyranose, d-glucopyranose, d-galactopyranose, α-l-arabinofuranose, and α-l-fucopyranose residues. Approximate molecular weights of polysaccharide extracts were determined by HPLC (high-performance liquid chromatography). The best antioxidant activity was found in polysaccharide extract in DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging (39.03% at 800 μg/mL), CUPRAC (cupric reducing antioxidant capacity) (A: 387.50 μg/mL), and PRAP (phosphomolybdenum reducing antioxidant power) (A: 384.08 μg/mL) assays. polysaccharide extract showed the highest antioxidant activity in ABTS scavenging (IC: 734.09 μg/mL), β-carotene-linoleic acid (IC: 472.16 μg/mL), and iron chelating (IC: 180.35 μg/mL) assays. Significant anticancer activity was found in polysaccharide extract on HT-29 (IC: 46.49 μg/mL) and HepG2 (IC: 48.50 μg/mL) cell lines and polysaccharide extract on the HeLa cell line (IC: 51.64 μg/mL). Also, polysaccharide extract possessed prominent AChE (acetylcholinesterase) inhibition activity (49.14% at 200 μg/mL).
PubMed: 38911755
DOI: 10.1021/acsomega.4c00322 -
Foods (Basel, Switzerland) May 2024L-Arabinose isomerase (L-AI) has been commonly used as an efficient biocatalyst to produce D-tagatose via the isomerization of D-galactose. However, it remains a...
L-Arabinose isomerase (L-AI) has been commonly used as an efficient biocatalyst to produce D-tagatose via the isomerization of D-galactose. However, it remains a significant challenge to efficiently synthesize D-tagatose using the native (wild type) L-AI at an industrial scale. Hence, it is extremely urgent to redesign L-AI to improve its catalytic efficiency towards D-galactose, and herein a structure-based molecular modification of CY6 L-AI (LpAI) was performed. Among the engineered LpAI, both F118M and F279I mutants showed an increased D-galactose isomerization activity. Particularly, the specific activity of double mutant F118M/F279I towards D-galactose was increased by 210.1% compared to that of the wild type LpAI (WT). Besides the catalytic activity, the substrate preference of F118M/F279I was also largely changed from L-arabinose to D-galactose. In the enzymatic production of D-tagatose, the yield and conversion ratio of F118M/F279I were increased by 81.2% and 79.6%, respectively, compared to that of WT. Furthermore, the D-tagatose production of whole cells expressing F118M/F279I displayed about 2-fold higher than that of WT cell. These results revealed that the designed site-directed mutagenesis is useful for improving the catalytic efficiency of LpAI towards D-galactose.
PubMed: 38890956
DOI: 10.3390/foods13111727 -
Foods (Basel, Switzerland) May 2024In the last decade, "expressions" of grape marc spirits aged in wooden barrels of characteristic amber color and complex sensory attributes have been introduced. Yet...
In the last decade, "expressions" of grape marc spirits aged in wooden barrels of characteristic amber color and complex sensory attributes have been introduced. Yet studies on constituents migrating from the barrel to the beverage are scarce, and their metabolic profile remains unexplored. Furthermore, the literature on the assessment of their antioxidant activity is limited. NMR metabolomics and spectrophotometry have been implemented in 38 samples to elucidate the impact of the aging procedure on the metabolites' composition and establish whether these beverages exhibit antioxidant activity. Provenance was related to fusel alcohols, esters, acetaldehyde, methanol, saccharides, and 2-phenylethanol, while ethyl acetate and ethyl lactate contributed to discriminating samples of the same winery. Identified metabolites such as vanillin, syringaldehyde, and sinapaldehyde were related to the aging procedure. The maturation in the barrel was also associated with an increase in xylose, glucose, fructose, and arabinose. The antioxidant potential of the aged Greek grape marc spirits resulting from their maturation in oak barrels was highlighted. The metabolic profiling and antioxidant potential of aged Greek grape marc spirits were assessed for the first time. Finally, the enrichment of the aromatic region was noted with the presence of metabolites with a furanic and phenolic ring derived, respectively, from the polysaccharides' degradation or the thermal decomposition of lignin.
PubMed: 38890893
DOI: 10.3390/foods13111664 -
Scientific Reports Jun 2024The mucus surface layer serves vital functions for scleractinian corals and consists mainly of carbohydrates. Its carbohydrate composition has been suggested to be...
The mucus surface layer serves vital functions for scleractinian corals and consists mainly of carbohydrates. Its carbohydrate composition has been suggested to be influenced by environmental conditions (e.g., temperature, nutrients) and microbial pressures (e.g., microbial degradation, microbial coral symbionts), yet to what extend the coral mucus composition is determined by phylogeny remains to be tested. To investigate the variation of mucus carbohydrate compositions among coral species, we analyzed the composition of mucosal carbohydrate building blocks (i.e., monosaccharides) for five species of scleractinian corals, supplemented with previously reported data, to discern overall patterns using cluster analysis. Monosaccharide composition from a total of 23 species (belonging to 14 genera and 11 families) revealed significant differences between two phylogenetic clades that diverged early in the evolutionary history of scleractinian corals (i.e., complex and robust; p = 0.001, R = 0.20), mainly driven by the absence of arabinose in the robust clade. Despite considerable differences in environmental conditions and sample analysis protocols applied, coral phylogeny significantly correlated with monosaccharide composition (Mantel test: p < 0.001, R = 0.70). These results suggest that coral mucus carbohydrates display phylogenetic dependence and support their essential role in the functioning of corals.
Topics: Anthozoa; Animals; Phylogeny; Mucus; Carbohydrates; Monosaccharides
PubMed: 38890484
DOI: 10.1038/s41598-024-64828-5 -
Metabolomics : Official Journal of the... Jun 2024The coral holobiont is underpinned by complex metabolic exchanges between different symbiotic partners, which are impacted by environmental stressors. The chemical...
The coral holobiont is underpinned by complex metabolic exchanges between different symbiotic partners, which are impacted by environmental stressors. The chemical diversity of the compounds produced by the holobiont is high and includes primary and secondary metabolites, as well as volatiles. However, metabolites and volatiles have only been characterised in isolation so far. Here, we applied a paired metabolomic-volatilomic approach to characterise holistically the chemical response of the holobiont under stress. Montipora mollis fragments were subjected to high-light stress (8-fold higher than the controls) for 30 min. Photosystem II (PSII) photochemical efficiency values were 7-fold higher in control versus treatment corals immediately following high-light exposure, but returned to pre-stress levels after 30 min of recovery. Under high-light stress, we identified an increase in carbohydrates (> 5-fold increase in arabinose and fructose) and saturated fatty acids (7-fold increase in myristic and oleic acid), together with a decrease in fatty acid derivatives in both metabolites and volatiles (e.g., 80% decrease in oleamide and nonanal), and other antioxidants (~ 85% decrease in sorbitol and galactitol). These changes suggest short-term light stress induces oxidative stress. Correlation analysis between volatiles and metabolites identified positive links between sorbitol, galactitol, six other metabolites and 11 volatiles, with four of these compounds previously identified as antioxidants. This suggests that these 19 compounds may be related and share similar functions. Taken together, our findings demonstrate how paired metabolomics-volatilomics may illuminate broader metabolic shifts occurring under stress and identify linkages between uncharacterised compounds to putatively determine their functions.
Topics: Animals; Anthozoa; Metabolomics; Light; Stress, Physiological; Volatile Organic Compounds; Photosystem II Protein Complex
PubMed: 38886248
DOI: 10.1007/s11306-024-02136-9 -
Journal of Applied Glycoscience 2024Super Ohtaka, a fermented beverage of plant extracts, is prepared from approximately 50 kinds of fruits and vegetables. Natural fermentation is mainly performed by...
Super Ohtaka, a fermented beverage of plant extracts, is prepared from approximately 50 kinds of fruits and vegetables. Natural fermentation is mainly performed by lactic acid bacteria ( spp.) and yeast ( spp.). Four water-soluble polysaccharide fractions were obtained from Super Ohtaka by dialysis, ion exchange chromatography, and gel filtration chromatography; these fractions were designated as OEP1-1, OEP1-2, OEP2, and OEP3. OEP1-1 is a polysaccharide composed solely of glucose. The other fractions contained polysaccharides composed of glucose, galactose, mannose, and a small amount of arabinose. OEP2 and OEP3 contained phosphorus, which was not detected in OEP1-1 and OEP1-2. Furthermore, the immunomodulatory activity of the polysaccharides was investigated in murine macrophage cell lines. OEP2 and OEP3 significantly induced nitric oxide (NO) secretion by macrophages in a dose-dependent manner (concentration range of 4 to 100 µg/mL). When the concentration of OEP3 was 100 µg/mL, NO production was almost identical to lipopolysaccharide (LPS; 10 ng/mL) used as a positive control. Notably, OEP3 induced NO secretion more strongly than OEP2. This trend was also observed for TNF-α, IL-1β, IL-6, and IL-12 p40 secretion. Overall, our studies on polysaccharides isolated from Super Ohtaka suggest that the fermented beverage stimulates macrophages and activates the immune system.
PubMed: 38863952
DOI: 10.5458/jag.jag.JAG-2023_0012 -
Frontiers in Veterinary Science 2024In this study, the polysaccharides (PCPs) were heteropolysaccharides with molecular weights of 63.17 kDa and 8.99 kDa, and their total carbohydrate content was...
In this study, the polysaccharides (PCPs) were heteropolysaccharides with molecular weights of 63.17 kDa and 8.99 kDa, and their total carbohydrate content was 76.17 ± 0.23%, uronic acid content was 19.92 ± 0.42%, and protein content was 1.24 ± 0.07%. PCP is composed of arabinose, galactose, glucose, and glucuronic acid, with a molar ratio of 0.196:0.249:0.451:0.104. In addition, we further investigated the effects of the diet supplemented with different doses of PCP on growth performance, meat quality, and anti-oxidant capacity in Chongren Partridge chickens. A total of 200 chickens were randomly allocated into 4 treatments, and fed with a basal diet of 0 (CON), 200 (LPCP), 400 (MPCP), and 800 (HPCP) mg/kg PCP for a 14-day prefeeding period and a formal experimental period of 56 days. Results showed that dietary PCP significantly increased final body weight (BW), average daily gain (ADG), and decreased feed-to-gain ratio (F/G) from days 1 to 56. Meanwhile, dietary PCP reduced yellowness (b) values and increased redness (a) values at 24 h in breast muscles ( < 0.05). Furthermore, LPCP and MPCP significantly increased the level of guanylic acid (GMP) ( < 0.05). MPCP increased the content of free amino acids (isoleucine, leucine, lysine, methionine, threonine, valine, alanine, glutamic acid, serine, cysteine), total essential amino acid (EAA), total flavor amino acid (FAA), total AA, the content of fatty acids (c14:1, c16:1, and c22:2), and monounsaturated fatty acids (MUFAs) in the breast muscle when compared to CON ( < 0.05). In addition, MPCP significantly reduced the content of malondialdehyde (MDA) and increased the transcript abundances of fatty acid desaturase 2 (), fatty acid synthase (), lipoprotein lipase (), and sterol regulatory element binding protein-1 () in the breast muscles of the chickens ( < 0.05). In light of the aforementioned results, PCP at 400 mg/kg could be used as an effective additive because it not only promotes the growth performance of Chongren Partridge chickens but also shows a conducive role in meat quality, especially in meat flavor.
PubMed: 38863448
DOI: 10.3389/fvets.2024.1381188 -
International Journal of Biological... Jun 2024To explore the adjuvant therapy drugs of low-dose metformin, one homogeneous polysaccharide named APS-D1 was purified from Astragalus membranaceus by DEAE-52 cellulose...
To explore the adjuvant therapy drugs of low-dose metformin, one homogeneous polysaccharide named APS-D1 was purified from Astragalus membranaceus by DEAE-52 cellulose and Sephadex G-100 column chromatography. Its chemical structure was characterized by molecular weight distribution, monosaccharide composition, infrared spectrum, methylation analysis, and NMR. The results revealed that APS-D1 (7.36 kDa) consisted of glucose, galactose, and arabinose (97.51 %:1.56 %:0.93 %). It consisted of →4)-α-D-Glcp-(1→ residue backbone with →3)-β-D-Galp-(1→ residue and terminal-α/β-D-Glcp-(1→ side chains. APS-D1 could significantly improve inflammation (TNF-α, LPS, and IL-10) in vivo. Moreover, APS-D1 improved the curative effect of low-dose metformin without adverse events. APS-D1 combined with low-dose metformin regulated several gut bacteria, in which APS-D1 enriched Staphylococcus lentus to produce l-carnitine (one of 136 metabolites of S. lentus). S. lentus and l-carnitine could improve diabetes, and reduction of S. lentusl-carnitine production impaired diabetes improvement. The combination, S. lentus, and l-carnitine could promote fatty acid oxidation (CPT1) and inhibit gluconeogenesis (PCK and G6Pase). The results indicated that APS-D1 enhanced the curative effect of low-dose metformin to improve diabetes by enriching S. lentus, in which the effect of S. lentus was mediated by l-carnitine. Collectively, these findings support that low-dose metformin supplemented with APS-D1 may be a favorable therapeutic strategy for type 2 diabetes.
Topics: Metformin; Animals; Polysaccharides; Staphylococcus; Mice; Astragalus Plant; Male; Diabetes Mellitus, Experimental; Hypoglycemic Agents; Molecular Weight
PubMed: 38834117
DOI: 10.1016/j.ijbiomac.2024.132860 -
A syrup containing L-arabinose and D-xylose appears superior to PEG-4000 as a bowel cleansing agent.AMB Express Jun 2024Adequate bowel cleansing is crucial for endoscopic diagnosis and treatment, and the recovery of gut microbiota after intestinal cleansing is also important. A hypertonic...
Adequate bowel cleansing is crucial for endoscopic diagnosis and treatment, and the recovery of gut microbiota after intestinal cleansing is also important. A hypertonic syrup predominantly comprising L-arabinose and D-xylose (20% xylo-oligosaccharides) can be extracted from the hemicellulose of corn husks and cobs. L-Arabinose and xylo-oligosaccharides have been reported to relieve constipation and improve the gut microbial environment. This study evaluated the bowel cleansing effect of the aforementioned syrup and its influence on the organism and intestinal microbiota after cleansing in comparison with polyethylene glycol-4000 (PEG-4000) in mice. Bowel cleansing was performed using syrup or PEG-4000 in C57BL/6J mice, and the effect of intestinal preparation and its influence on serum electrolytes and gut microbiota after bowel cleansing were evaluated. The volume of intestinal residual feces in the syrup group was significantly lower than that in the PEG-4000 group. Additionally, syrup disturbed serum electrolytes more mildly than PEG-4000. Alpha diversity in the gut microbiota was significantly higher in the syrup group than in the PEG-4000 group on the first day after bowel cleansing. However, no difference in beta diversity was observed between the two groups. Syrup increased the abundance of Bifidobacteria and Christensenella and decreased the abundance of Akkermansia in comparison with PEG-4000 on the first day after bowel cleansing. Thus, this syrup has potential clinical use as a bowel cleansing agent given the above effects, its benefits and safety, and better taste and acceptability.
PubMed: 38824272
DOI: 10.1186/s13568-024-01715-2